1. Joanne M. Atlee and Stefania Gnesi, editors. Proceedings 6th Workshop on Formal Methods and Analysis in SPL Engineering, FMSPLE@ETAPS 2015, London, UK, 11 April 2015, volume 182 of EPTCS, 2015. [WWW] [doi:10.4204/EPTCS.182] [bibtex-key = DBLP:journals/corr/AtleeG15]
  2. H. Betz, T. Frühwirth, and U. Schöning. A Unified Analytical Foundation for Constraint Handling Rules. Books on Demand, 2014. ISBN: 9783734732508. [bibtex-key = betz2014unified]
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  4. R. Kowalski and T. Frühwirth. Logic for Problem Solving, Revisited, Computer science essentials. Books on Demand, 2014. ISBN: 9783837036299. [bibtex-key = kowalski2014logic]
  5. Jacopo Mauro. Constraints Meet Concurrency. Atlantis Publishing Corporation, 2014. ISBN: 9462390665, 9789462390669. [bibtex-key = Mauro:2014:CMC:2597626]
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  7. 26th IEEE International Conference on Tools with Artificial Intelligence, ICTAI 2014, Limassol, Cyprus, November 10-12, 2014, 2014. IEEE Computer Society. ISBN: 978-1-4799-6572-4. [WWW] [bibtex-key = DBLP:conf/ictai/2014]
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  16. Hendrik Skubch. Modelling and Controlling of Behaviour for Autonomous Mobile Robots. Springer Science & Business Media, 2012. [bibtex-key = skubch2012modelling]
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  20. Jon Sneyers and Thom Frühwirth, editors. CHR12l, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): CHR 2012. [bibtex-key = pchr12]
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  22. John Gallagher and Michael Gelfond, editors. ICLP11l, volume 11(4--5) of TPLP. CUP, July 2011. [bibtex-key = piclp11]
  23. John Gallagher and Michael Gelfond, editors. Technical Communications of the 27th Intl. Conf. on Logic Programming, volume 11 of Leibniz Intl. Proc. in Informatics (LIPIcs), Dagstuhl, Germany, July 2011. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik. [bibtex-key = tciclp11]
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  28. Manuel Hermenegildo and Torsten Schaub, editors. ICLP10l, volume 10(4--6) of TPLP. CUP, July 2010. [bibtex-key = piclp10]
  29. M. Montali. Specification and Verification of Declarative Open Interaction Models: A Logic-Based Approach, volume 56. Springer-Verlag New York Inc, 2010. [bibtex-key = montali2010specification]
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  35. A. Wolf and U. Geske, editors. WLP '09: Proc. 23rd Workshop on (Constraint) Logic Programming, 2010. Universität Potsdam. [WWW] [bibtex-key = pwlp09]
  36. Thom Frühwirth. Constraint Handling Rules. CUP, August 2009. ISBN: 9780521877763. [WWW] Keyword(s): tutorial. [bibtex-key = fru_chr_book_2009]
  37. M. Hanus, editor. LOPSTR08l, volume 5438 of LNCS, 2009. SV. [doi:10.1007/978-3-642-00515-2] [bibtex-key = plopstr08]
  38. Patricia M. Hill and David S. Warren, editors. ICLP09l, volume 5649 of LNCS, July 2009. SV. [doi:10.1007/978-3-642-02846-5] [bibtex-key = piclp09]
  39. F.J. López-Fraguas, editor. PPDP09l, September 2009. ACM. [bibtex-key = pppdp09]
  40. F. Raiser and J. Sneyers, editors. CHR09l, July 2009. KULCW, Technical report CW 555. Keyword(s): CHR 2009. [bibtex-key = pchr09]
  41. Tom Schrijvers and Thom Frühwirth, editors. Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8] [bibtex-key = lnai08]
  42. M. Garcìa de la Banda and E. Pontelli, editors. ICLP08l, volume 5366 of LNCS, December 2008. SV. [doi:10.1007/978-3-540-89982-2] [bibtex-key = piclp08]
  43. M. Hanus, editor. LOPSTR08prel, 2008. [WWW] [PDF] [bibtex-key = plopstr08pre]
  44. A. King, editor. LOPSTR07l, volume 4915 of LNCS, 2008. [bibtex-key = plopstr07]
  45. T. Schrijvers, F. Raiser, and T. Frühwirth, editors. CHR08l, 2008. RISC Report Series 08-10, University of Linz, Austria. Keyword(s): CHR 2008. [bibtex-key = pchr08]
  46. V. Dahl and I. Niemelä, editors. ICLP07l, volume 4670 of LNCS, September 2007. SV. [doi:10.1007/978-3-540-74610-2] [bibtex-key = piclp07]
  47. K. Djelloul, G. J. Duck, and M. Sulzmann, editors. CHR07l, September 2007. Keyword(s): CHR 2007. [bibtex-key = pchr07]
  48. M. Leuschel and A. Podelski, editors. PPDP07l, July 2007. ACM. ISBN: 978-1-59593-769-8. [bibtex-key = pppdp07]
  49. A. Bossi and M.J. Maher, editors. PPDP06l, July 2006. ACM. ISBN: 1-59593-388-3. [bibtex-key = pppdp06]
  50. S. Etalle and M. Truszczynski, editors. ICLP06l, volume 4079 of LNCS, August 2006. SV. [doi:10.1007/11799573] [bibtex-key = piclp06]
  51. M. Fink, H. Tompits, and S. Woltran, editors. WLP '06: Proc. 20th Workshop on Logic Programming, T.U.Wien, Austria, INFSYS Research report 1843-06-02, February 2006. [bibtex-key = pwlp06]
  52. N. Kobayashi, editor. APLAS '06: Proc. 4th Asian Symp. on Programming Languages and Systems, volume 4279 of LNCS, November 2006. SV. ISBN: 3-540-48937-1. [bibtex-key = paplas06]
  53. T. Schrijvers and Th. Frühwirth, editors. CHR06l, July 2006. KULCW, Technical report CW 452. Keyword(s): CHR 2006. [bibtex-key = pchr06]
  54. Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors. Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming. CUP, July 2005. [bibtex-key = tplp05]
  55. P. Barahona and A.P. Felty, editors. PPDP05l, July 2005. ACM. ISBN: 1-59593-090-6. [bibtex-key = pppdp05]
  56. M. Gabbrielli and G. Gupta, editors. ICLP05l, volume 3668 of LNCS, October 2005. SV. [bibtex-key = piclp05]
  57. T. Schrijvers and Th. Frühwirth, editors. CHR05l, 2005. KULCW, Technical report CW 421. Keyword(s): CHR 2005. [bibtex-key = pchr05]
  58. A. Wolf, Th. Frühwirth, and M. Meister, editors. W(C)LP '05: Proc. 19th Workshop on (Constraint) Logic Programming, volume 2005-01 of UIB, February 2005. [WWW] [bibtex-key = pwclp05]
  59. B. Demoen and V. Lifschitz, editors. ICLP04l, volume 3132 of LNCS, September 2004. SV. ISBN: 978-3-540-22671-0. [doi:10.1007/b99475] [bibtex-key = piclp04]
  60. Th. Frühwirth and M. Meister, editors. CHR04l, May 2004. Keyword(s): CHR 2004. [bibtex-key = pchr04]
  61. Thom Frühwirth and Slim Abdennadher. Essentials of Constraint Programming. SV, 2003. ISBN: 3540676236. Keyword(s): tutorial. [bibtex-key = fru_abd_essentials_of_cp_book03]
  62. F. Buccafurri, editor. AGP '03: Joint Conf. Declarative Programming APPIA-GULP-PRODE, September 2003. [bibtex-key = pagp03]
  63. M. Hanus, editor. WFLP '01: Proc. 10th Intl. Workshop on Functional and (Constraint) Logic Programming, Selected Papers, volume 64 of ENTCS, November 2002. Elsevier. [bibtex-key = pwflp01:entcs02]
  64. P. J. Stuckey, editor. ICLP02l, volume 2401 of LNCS, jul/aug 2002. SV. [bibtex-key = piclp02]
  65. R. De Nicola and H. Sondergaard, editors. PPDP01l, September 2001. ACM. ISBN: 1-58113-388-X. [bibtex-key = pppdp01]
  66. C. Holzbaur and Th. Frühwirth, editors. Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence. Taylor & Francis, April 2000. [bibtex-key = aai00]
  67. K.R. Apt, A.C. Kakas, E. Monfroy, and F. Rossi, editors. New Trends in Constraints, Joint ERCIM/Compulog Net Workshop, October 1999, Selected papers, volume 1865 of LNCS, 2000. SV. ISBN: 3-540-67885-9. [bibtex-key = pcompulog99]
  68. T. Frühwirth and others, editors. RCoRP '00(bis): Proc. 2nd Workshop on Rule-Based Constraint Reasoning and Programming, September 2000. [bibtex-key = prcorp00bis]
  69. T. Frühwirth and others, editors. RCoRP '00: Proc. 1st Workshop on Rule-Based Constraint Reasoning and Programming, July 2000. [bibtex-key = rcorp00]
  70. J. Jaffar, editor. CP99l, volume 1713 of LNCS, October 1999. SV. ISBN: 3-540-66626-5. [bibtex-key = pcp99]
  71. Marìa Teresa Escrig Monferrer and Francisco Toledo Lobo. Qualitative Spatial Reasoning: Theory and Practice --- Application to Robot Navigation. IOS Press, 1998. [bibtex-key = escrig_toledo_qual_spatial_reasoning_book98]
  72. T. Andreasen, H. Christiansen, and H.L. Larsen, editors. FQAS '98: Proc. 3rd Intl. Conf. on Flexible Query Answering Systems, volume 1495 of LNAI, May 1998. SV. [bibtex-key = pfqas98]
  73. M. J. Maher and J.-F. Puget, editors. CP98l, volume 1520 of LNCS, October 1998. SV. ISBN: 3-540-65224-8. [bibtex-key = pcp98]
  74. Ed Robbins. Solvers for Type Recovery and Decompilation of Binaries. PhD thesis, University of Kent, 2017. [bibtex-key = robbins2017solvers]
  75. Zsolt Zombori. Prolog Based Reasoning. PhD thesis, University of Technology and Economics Budapest, 2013. [bibtex-key = zombori2013thesis]
  76. Jacopo Mauro. Constraints meet concurrency. PhD thesis, 2012. [bibtex-key = mauro2012thesis]
  77. Tobias Rho. A Statically Typed Logic Context Query Language With Parametric Polymorphism and Subtyping. PhD thesis, Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Diss., 2012, 2012. [bibtex-key = rho2012statically]
  78. Edmund S.L. Lam. Parallel execution of Constraint Handling Rules -- Theory, Implementation and Application. PhD thesis, School of Computing, Department of Computing Science, National University of Singapore, 2011. Keyword(s): parallelism, implementation. [bibtex-key = lam_parallel_chr_11]
  79. Frank Raiser. Graph Transformation Systems in Constraint Handling Rules: Improved Methods for Program Analysis. PhD thesis, Ulm University, Germany, November 2010. [WWW] [PDF] Keyword(s): Graph Transformation Systems, related formalisms.
    Abstract:
    Constraint Handling Rules (CHR) is a rule- and logic-based formalism and has established itself as an active research topic. In contrast to other rule-based approaches, CHR is both, a theoretical formalism related to first-order and linear-logic, and a practical rule-based programming language. Other rule- and logic-based approaches have been successfully embedded in CHR. For this reason, it is considered a candidate for a lingua-franca of such approaches. We investigate CHR´s suitability for this purpose exemplarily, by considering an embedding of graph transformation systems (GTSs) in CHR, which helps us in identifying points of improvements for strengthening the lingua-franca argument further. In particular, we present a novel formulation of the operational semantics of CHR, which is founded on an equivalence relation over CHR states. It justifies the perspective on CHR as a rule-based rewriting system of equivalence classes, which abstracts over infinitely many possible syntactic variations of a CHR state. Overall, this equivalence-based operational semantics provides a powerful formal analysis tool for CHR, which can significantly reduce proof complexity. The lingua-franca argument implies a potential for cross-fertilization of research. Hence, we revisit program analysis methods available in the CHR literature. Our extended methods apply an invariant to make implicit assumptions explicitly available during analysis, hence, effectively eliminating irrelevant states. The resulting methods are applicable to strictly larger classes of CHR programs and provide more promising approaches towards analyzing more complex programs. Finally, we compare program analysis methods in GTSs and CHR. We find that the adapted CHR confluence test, when applied to a GTS embedded in CHR, corresponds to a sufficient criterion for confluence of the GTS. Similarly, we introduce program equivalence for GTSs with a sufficient criterion based on the CHR program equivalence test.
    [bibtex-key = raiser_phdthesis10]
  80. Peter Van Weert. Extension and Optimising Compilation of Constraint Handling Rules. PhD thesis, K.U.Leuven, Belgium, May 2010. [WWW] [PDF] Keyword(s): implementation, optimizing compilation, Java.
    Abstract:
    Constraint Handling Rules (CHR) is a high-level declarative programming language based on multi-headed multiset rewrite rules, combined with aspects of logic and constraint programming. Originally designed for extending a host language with user-defined constraint solvers, CHR has evolved into a powerful, elegant general-purpose language with a wide spectrum of application domains. The goal of this dissertation is to further improve the practical usability of the CHR programming language. As a first step, we therefore redesign the language's syntax, language features, and operational semantics to allow a more high-level, declarative programming style. Our streamlined CHR2 syntax allows for more natural, readable, and concise rule definitions. The operational semantics of CHR2 programs is designed to be as non-deterministic as possible, while still facilitating the effective execution control required for practical programming. In line with the `what, not how' and `algorithm = logic + control' maxims of declarative programming, the CHR2 system by default fully determines the execution strategy. % When needed though, the programmer may control the order in which rules and conjunctions are executed using two orthogonal, familiar execution control constructs: rule priorities and sequential conjunction. Priorities are specified using symbolic priority constraints, which are more flexible than earlier proposals, and offer a better separation of logic and control. We furthermore extended CHR with expressive language abstractions called aggregates. Aggregates are powerful, concise rule applicability conditions that collect information from larger parts of the constraint store. Well-known examples include exttt{min}, exttt{sum}, exttt{count}, and exttt{findall}. Our proposed framework supports nested aggregate expressions, efficient incremental aggregate computation and application-tailored user-defined aggregates. Aggregates eliminate the need for low-level encodings of aggregate computations commonly found in CHR programs. The extended CHR language thus fully regains its high-level, declarative nature. A next crucial aspect of the practical usability of any programming language is the performance of its implementations. Because CHR2 rules are written at a very high level of abstraction, uncovering the optimal low-level execution steps required to evaluate them is very challenging. In the final part of the dissertation, we therefore introduce, evaluate and refine many new and existing analyses and optimisation techniques for CHR programs. Two instances are discussed in more detail: We revise CHR's compilation scheme to optimise the space consumption of recursive programs, and develop novel techniques for optimal---both in space and in time---reapplication prevention of CHR propagation rules. Lastly, for CHR to be really useful for practical applications, CHR must be embedded in a mainstream host language. We therefore developed K.U.Leuven JCHR, a state-of-the-art CHR system for Java. The thesis addresses both the language design issues of integrating CHR with imperative host languages, and the technical challenges faced when compiling CHR to imperative languages. JCHR is currently one of the most complete and efficient CHR implementations available, typically outperforming other rule-based systems by several orders of magnitude. The next-generation \JCHRtwo\ system moreover is a first reference implementation of the improved \CHRtwo\ language, extended with negation as absence.
    [bibtex-key = vanweert_phdthesis10]
  81. Cinzia Di Giusto. Expressiveness of Concurrent Languages. PhD thesis, deptcw, University of Bologna, Italy, March 2009. [PDF] Keyword(s): expressivity. [bibtex-key = digiusto_phdthesis09]
  82. Jairson Vitorino. Model-Driven Engineering a Versatile, Extensible, Scalable Rule Engine through Component Assembly and Model Transformations. PhD thesis, Federal University of Pernambuco, Recife, Brazil, February 2009. [bibtex-key = vitorino_phdthesis09]
  83. Leslie De Koninck. Execution Control for Constraint Handling Rules. PhD thesis, K.U.Leuven, Belgium, November 2008. [WWW] [PDF] Keyword(s): priorities, complexity, related formalisms.
    Abstract:
    Constraint Programming (CP) is a high-level declarative programming paradigm in which problems are modeled by means of constraints on the problem variables that need to hold in all solutions to the problem. Many problems of high practical relevance can easily be described in terms of constraints. Example application areas include production planning and crew scheduling. A constraint programming system contains a constraint solver whose task it is to find valuations for the problem variables that satisfy all constraints. Constraint programming systems can be classified by the variable domains and types of constraints their solver supports. However, for many problems it is not so straightforward to create a model in terms of basic constraint domains. Therefore, on the one hand, systems emerged that can handle more specialized constraint domains. On the other hand, facilities were designed that make it easier to implement an application-specific constraint solver. Some notable examples of these facilities are attributed variables, and Constraint Handling Rules. Constraint Handling Rules (CHR) is a rule-based language, designed for the implementation of application-specific constraint solvers. CHR is a very flexible language for the specification of a constraint solvers' logic, but flexible execution control is almost completely lacking. Execution control is of great importance for the efficiency of CP systems. However, so far, the problem of execution control has received only very limited attention in the context of CHR. In this thesis, we propose a solution to the problem of execution control in CHR. In particular, we extend CHR with high-level facilities to support the specification of execution strategies. More precisely, we extend CHR with user-defined rule priorities into CHR$^\mathrm{rp}$. CHR rules correspond to constraint propagators, and so rule priorities enable the specification of propagation strategies. An optimized implementation of CHR$^\mathrm{rp}$ is presented and evaluated empirically. Next, we extend CHR with facilities for search strategy control. Our approach combines CHR$^\vee$ (CHR with disjunction) and CHR$^\mathrm{rp}$ into a new language called CHR$_\vee^\mathrm{brp}$ in which the propagation strategy is determined by means of rule priorities, and the search strategy by means of branch priorities. We propose a framework for analyzing the time complexity of CHR$^\mathrm{rp}$ programs, by combining the Logical Algorithms framework (LA) of Ganzinger and McAllester with CHR$^\mathrm{rp}$. We present translation schemas from and to LA and propose an alternative implementation for CHR$^\mathrm{rp}$ with strong complexity guarantees. Finally, we investigate the join order optimization problem, which is an important aspect of optimized CHR compilation. We propose a cost model for matching multi-headed rules, approximations of its parameters, and methods to find an optimal join order. An extension of the model for CHR$^\mathrm{rp}$ is given.
    [bibtex-key = dekoninck_phdthesis08]
  84. Mark Meister. Advances in Constraint Handling Rules. PhD thesis, Universität Ulm, Germany, 2008. [bibtex-key = meister_thesis2008]
  85. Jon Sneyers. Optimizing Compilation and Computational Complexity of Constraint Handling Rules. PhD thesis, K.U.Leuven, Belgium, November 2008. [WWW] [PDF] Keyword(s): implementation, optimizing compilation, complexity, computability.
    Abstract:
    Constraint Handling Rules (CHR) is a very-high-level declarative programming language based on concurrent multiset rewrite rules that are conditional, multi-headed, and committed-choice. Originally designed in the early 1990s as a special-purpose programming language for adding user-defined constraint solvers to a host language, CHR has evolved over the last decade into a powerful and elegant general-purpose language with a wide spectrum of application domains. Computational complexity theory is the study of scalability of computer programs in terms of the computational resources they require --- in particular, time (cpu usage) and space (memory usage). In this dissertation we investigate the CHR programming language from the point of view of computational complexity theory. The first part introduces complexity theory, CHR, and CHR compilation. In the second part, we improve the state of the art by proposing and implementing several compiler optimizations. We confirm experimentally that these optimizations improve both the time and space complexity of CHR programs. Finally, in the third part of this dissertation, we prove a ``complexity-wise completeness'' result. We demonstrate that the CHR language and state-of-the-art CHR systems (that implement the compiler optimizations of the previous part) are sufficiently efficient in the following precise sense: \emph{every algorithm can be implemented in CHR and be executed with the optimal asymptotic time and space complexity}.
    [bibtex-key = sneyers_phdthesis08]
  86. Paolo Tacchella. Constraint Handling Rules --- Compositional Semantics and Program Transformation. PhD thesis, deptcw, University of Bologna, Italy, March 2008. [WWW] [PDF] Keyword(s): semantics.
    Abstract:
    This thesis intends to investigate two aspects of Constraint Handling Rules (CHR). It proposes a compositional semantics and a technique for program transformation. CHR is a concurrent committed-choice constraint logic programming language consisting of guarded rules, which transform multi-sets of atomic formulas (constraints) into simpler ones until exhaustion and it belongs to the declarative languages family. It was initially designed for writing constraint solvers but it has recently also proven to be a general purpose language, being as it is Turing equivalent. Compositionality is the first CHR aspect to be considered. A trace based compositional semantics for CHR was previously defined. The reference operational semantics for such a compositional model was the original operational semantics for CHR which, due to the propagation rule, admits trivial non-termination. In this thesis we extend the above mentioned work by introducing a more refined trace based compositional semantics which also includes the history. The use of history is a well-known technique in CHR which permits us to trace the application of propagation rules and consequently it permits trivial non-termination avoidance. Naturally, the reference operational semantics, of our new compositional one, uses history to avoid trivial non-termination too. Program transformation is the second CHR aspect to be considered, with particular regard to the unfolding technique. Said technique is an appealing approach which allows us to optimize a given program and in more detail to improve run-time efficiency or space-consumption. Essentially it consists of a sequence of syntactic program manipulations which preserve a kind of semantic equivalence called qualified answer, between the original program and the transformed ones. The unfolding technique is one of the basic operations which is used by most program transformation systems. It consists in the replacement of a procedure-call by its definition. In CHR every conjunction of constraints can be considered as a procedure-call, every CHR rule can be considered as a procedure and the body of said rule represents the definition of the call. While there is a large body of literature on transformation and unfolding of sequential programs, very few papers have addressed this issue for concurrent languages. We define an unfolding rule, show its correctness and discuss some conditions in which it can be used to delete an unfolded rule while preserving the meaning of the original program. Finally, confluence and termination maintenance between the original and transformed programs are shown.
    [bibtex-key = tacchella_thesis2008]
  87. Kimberly Voll. A methodology of error detection: Improving speech recognition in radiology. PhD thesis, Simon Fraser University, Burnaby, Canada, 2006. [WWW] [bibtex-key = voll_thesis06]
  88. Jeremy Wazny. Type inference and type error diagnosis for Hindley/Milner with extensions. PhD thesis, University of Melbourne, Australia, 2006. Keyword(s): type systems. [bibtex-key = wazny_phdthesis06]
  89. Marco Alberti. A Computational Logic-based System for Specification and Verification of Agent Interaction. PhD thesis, University of Ferrara, Italy, 2005. [bibtex-key = alberti_phdthesis05]
  90. Alma Barranco-Mendoza. Stochastic and heuristic modelling for analysis of the growth of pre-invasive lesions and for a multidisciplinary approach to early cancer diagnosis. PhD thesis, Simon Fraser University, Burnaby, Canada, 2005. [WWW] [bibtex-key = alma_thesis05]
  91. Gregory J. Duck. Compilation of Constraint Handling Rules. PhD thesis, University of Melbourne, Australia, December 2005. Keyword(s): implementation, optimizing compilation. [bibtex-key = duck_phdthesis05]
  92. Tom Schrijvers. Analyses, optimizations and extensions of Constraint Handling Rules. PhD thesis, K.U.Leuven, Belgium, June 2005. [WWW] [PDF] [POSTSCRIPT] Keyword(s): implementation, optimizing compilation. [bibtex-key = schr_phdthesis05]
  93. Hongwei Zhu. Effective Information Integration and Reutilization: Solutions to Technological Deficiency and Legal Uncertainty. PhD thesis, Engineering Systems Division, Massachusetts Institute of Technology, Cambridge, MA, USA, September 2005. [bibtex-key = zhu_05]
  94. Aykut Firat. Information Integration Using Contextual Knowledge and Ontology Merging. PhD thesis, MIT Sloan School of Management, Cambridge, Massachusetts, USA, September 2003. [bibtex-key = firat_ecoin_phdthesis03]
  95. Slim Abdennadher. Rule-based Constraint Programming: Theory and Practice. Habilitationsschrift, Institute of Computer Science, LMU, Munich, Germany, July 2001. [bibtex-key = abd_habilitation_2001]
  96. Armin Wolf. Adaptive Constraintverarbeitung mit Constraint-Handling-Rules -- Ein allgemeiner Ansatz zur Lösung dynamischer Constraint-probleme. PhD thesis, Technical University Berlin, Germany, 1999. [bibtex-key = wolf_phdthesis99]
  97. Thom Frühwirth. A Declarative Language for Constraint Systems: Theory and Practice of Constraint Handling Rules. Habilitationsschrift, deptcw, LMU, Munchen, Germany, December 1997. [bibtex-key = fru_habilitation96]
  98. Samer Abdallah. Automatic Differentiation using Constraint Handling Rules in Prolog. arXiv preprint arXiv:1706.00231, 2017. [bibtex-key = abdallah2017automatic]
  99. Henning Christiansen and Maja H Kirkeby. On proving confluence modulo equivalence for Constraint Handling Rules. Formal Aspects of Computing, 29(1):57-95, 2017. [bibtex-key = christiansen2017proving]
  100. Emanuele De Angelis, Fabio Fioravanti, Alberto Pettorossi, and Maurizio Proietti. Program verification using constraint handling rules and array constraint generalizations. Fundamenta Informaticae, 150(1):73-117, 2017. [bibtex-key = de2017program]
  101. Maja H Kirkeby and Henning Christiansen. Confluence and Convergence in Probabilistically Terminating Reduction Systems. arXiv preprint arXiv:1709.05123, 2017. [bibtex-key = kirkeby2017confluence]
  102. Alejandro Serrano and Jurriaan Hage. Constraint handling rules with binders, patterns and generic quantification. Theory and Practice of Logic Programming, 17(5-6):992-1009, 2017. [bibtex-key = serrano2017constraint]
  103. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. Visualization of Constraint Handling Rules: Semantics and Applications. arXiv preprint arXiv:1706.01755, 2017. [bibtex-key = sharaf2017visualization]
  104. Henning Christiansen and Maja H Kirkeby. On proving confluence modulo equivalence for Constraint Handling Rules. Formal Aspects of Computing, pp 1-39, 2016. [bibtex-key = christiansen2016proving]
  105. Duc-Hanh DANG, Anh-Hoang TRUONG, and Van Hung DANG. On Model Finding with Constraint Patterns. New Trends in Software Methodologies, Tools and Techniques: Proceedings of the Fifteenth SoMeT_16, 286:279, 2016. [bibtex-key = dang2016model]
  106. Ferruccio Guidi, Claudio Coen, and Enrico Tassi. Implementing Type Theory in Higher Order Constraint Logic Programming. December 2016. [WWW] [bibtex-key = guidi2016implementing]
  107. Frédéric Lardeux and Eric Monfroy. Réduction et Encodage des Contraintes Ensemblistes en SAT. Douziemes Journees Francophones de Programmation par Contraintes, pp 153-162, 2016. [bibtex-key = lardeuxreduction]
  108. Thom Frühwirth. Why Can't You Behave? Non-termination Analysis of Direct Recursive Rules with Constraints, pages 208-222. Springer International Publishing, 2016. ISBN: 978-3-319-42019-6. [doi:10.1007/978-3-319-42019-6_14] [bibtex-key = fruehwirth2016]
  109. Daniel Gall and Thom Frühwirth. Translation of Cognitive Models from ACT-R to Constraint Handling Rules, pages 223-237. Springer International Publishing, 2016. [doi:10.1007/978-3-319-42019-6_15] [bibtex-key = gall2016]
  110. Fabian Büttner and Jordi Cabot. Lightweight string reasoning in model finding. Software & Systems Modeling, 14(1):413-427, 2015. ISSN: 1619-1374. [WWW] [doi:10.1007/s10270-013-0332-x]
    Abstract:
    Models play a key role in assuring software quality in the model-driven approach. Precise models usually require the definition of well-formedness rules to specify constraints that cannot be expressed graphically. The Object Constraint Language (OCL) is a de-facto standard to define such rules. Techniques that check the satisfiability of such models and find corresponding instances of them are important in various activities, such as model-based testing and validation. Several tools for these activities have been developed, but to our knowledge, none of them supports OCL string operations on scale that is sufficient for, e.g., model-based testing. As, in contrast, many industrial models do contain such operations, there is evidently a gap. We present a lightweight solver that is specifically tailored to generate large solutions for tractable string constraints in model finding, and that is suited to directly express the main operations of the OCL datatype String. It is based on constraint logic programming (CLP) and constraint handling rules, and can be seamlessly combined with other constraint solvers in CLP. We have integrated our solver into the EMFtoCSP model finder, and we show that our implementation efficiently solves several common string constraints on large instances.
    [bibtex-key = Büttner2015]
  111. Martin Sulzmann, Kai Stadtmüller, and Edmund S.L. Lam. Establishing a Correspondence between Transactional Events and Constraint Handling Rules. 2015. [PDF] [bibtex-key = sulzmannestablishing]
  112. Henning Christiansen and Maja H. Kirkeby. Confluence Modulo Equivalence in Constraint Handling Rules, pages 41-58. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-17822-6. [WWW] [doi:10.1007/978-3-319-17822-6_3] [bibtex-key = Christiansen2015]
  113. Flavio Cruz and Ricardo Rocha. On Compiling Linear Logic Programs with Comprehensions, Aggregates and Rule Priorities, pages 34-49. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-19686-2. [WWW] [doi:10.1007/978-3-319-19686-2_3] [bibtex-key = Cruz2015]
  114. Alia El Bolock and Slim Abdennadher. Satisfying Poetry Properties Using Constraint Handling Rules, pages 335-347. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-18117-2. [WWW] [doi:10.1007/978-3-319-18117-2_25] [bibtex-key = ElBolock2015]
  115. Ahmed Elsawy, Amira Zaki, and Slim Abdennadher. Exhaustive Execution of CHR Through Source-to-Source Transformation, pages 59-73. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-17822-6. [WWW] [doi:10.1007/978-3-319-17822-6_4] [bibtex-key = Elsawy2015]
  116. Daniel Gall and Thom Frühwirth. A Formal Semantics for the Cognitive Architecture ACT-R, pages 74-91. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-17822-6. [WWW] [doi:10.1007/978-3-319-17822-6_5] [bibtex-key = Gall2015]
  117. Michael Hanus. CHR(Curry): Interpretation and Compilation of Constraint Handling Rules in Curry, pages 74-89. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-19686-2. [WWW] [doi:10.1007/978-3-319-19686-2_6] [bibtex-key = Hanus2015]
  118. Edmund S.L. Lam, Iliano Cervesato, and Nabeeha Fatima. Comingle: Distributed Logic Programming for Decentralized Mobile Ensembles, pages 51-66. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-19282-6. [WWW] [doi:10.1007/978-3-319-19282-6_4] [bibtex-key = Lam2015]
  119. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. CHRAnimation: An Animation Tool for Constraint Handling Rules, pages 92-110. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-17822-6. [WWW] [doi:10.1007/978-3-319-17822-6_6] [bibtex-key = Sharaf2015]
  120. Rahul Singhal, Martin Henz, and Shubham Goyal. Artificial Intelligence in Education: 17th International Conference, AIED 2015, Madrid, Spain, June 22-26, 2015. Proceedings, chapter A Framework for Automated Generation of Questions Based on First-Order Logic, pages 776-780. Springer International Publishing, Cham, 2015. ISBN: 978-3-319-19773-9. [WWW] [doi:10.1007/978-3-319-19773-9_114] [bibtex-key = Singhal2015]
  121. Thom Frühwirth. Constraint Handling Rules-What Else?. In Rule Technologies: Foundations, Tools, and Applications, pages 13-34. Springer, 2015. [bibtex-key = fruhwirth2015constraint]
  122. Peter Bailis, Alan Fekete, Michael J. Franklin, Ali Ghodsi, Joseph M. Hellerstein, and Ion Stoica. Coordination Avoidance in Database Systems. Proc. VLDB Endow., 8(3):185-196, November 2014. ISSN: 2150-8097. [WWW] [doi:10.14778/2735508.2735509] [bibtex-key = Bailis:2014:CAD:2735508.2735509]
  123. Peter Bailis, Alan Fekete, Michael J. Franklin, Ali Ghodsi, Joseph M. Hellerstein, and Ion Stoica. Coordination-Avoiding Database Systems. CoRR, abs/1402.2237, 2014. [WWW] [bibtex-key = DBLP:journals/corr/BailisFFGHS14]
  124. Gregory J. Duck, Rémy Haemmerlé, and Martin Sulzmann. On Termination, Confluence and Consistent CHR-based Type Inference. Theory and Practice of Logic Programming, 14:619-632, 7 2014. ISSN: 1475-3081. [WWW] [doi:10.1017/S1471068414000246] [bibtex-key = duck2014termination]
  125. Daniel Gall and Thom Frühwirth. Exchanging Conflict Resolution in an Adaptable Implementation of ACT-R. Theory and Practice of Logic Programming, 14:525-538, 7 2014. ISSN: 1475-3081. [WWW] [doi:10.1017/S1471068414000180] [bibtex-key = gall2014conflictres]
  126. Falco Nogatz and Thom Frühwirth. From XML Schema to JSON Schema: Translation with CHR. Proceedings of the 11th International Workshop on Constraint Handling Rules, 2014. [WWW]
    Abstract:
    Despite its rising popularity as data format especially for web services, the software ecosystem around the JavaScript Object Notation (JSON) is not as widely distributed as that of XML. For both data formats there exist schema languages to specify the structure of instance documents, but there is currently no opportunity to translate already existing XML Schema documents into equivalent JSON Schemas. In this paper we introduce an implementation of a language translator. It takes an XML Schema and creates its equivalent JSON Schema document. Our approach is based on Prolog and CHR. By unfolding the XML Schema document into CHR constraints, it is possible to specify the concrete translation rules in a declarative way.
    [bibtex-key = journals/corr/NogatzF14]
  127. Aya Saad, Thom Frühwirth, and Carmen Gervet. The P-Box CDF-Intervals: A Reliable Constraint Reasoning with Quantifiable Information. Theory and Practice of Logic Programming, 14:461-475, 7 2014. ISSN: 1475-3081. [WWW] [doi:10.1017/S1471068414000143] [bibtex-key = saad2014pbox]
  128. Leonor Becerra-Bonache, Verónica Dahl, and M. Dolores Jiménez-López. Womb Grammars as a Bio-inspired Model for Grammar Induction, pages 79-86. Springer International Publishing, Cham, 2014. ISBN: 978-3-319-07476-4. [WWW] [doi:10.1007/978-3-319-07476-4_10] [bibtex-key = Becerra-Bonache2014]
  129. Henning Christiansen. Constraint Logic Programming for Resolution of Relative Time Expressions, pages 93-102. Springer International Publishing, Cham, 2014. ISBN: 978-3-319-08019-2. [WWW] [doi:10.1007/978-3-319-08019-2_10] [bibtex-key = Christiansen2014]
  130. Henning Christiansen. Constraint Programming for Context Comprehension, pages 401-418. Springer New York, New York, NY, 2014. ISBN: 978-1-4939-1887-4. [WWW] [doi:10.1007/978-1-4939-1887-4_25] [bibtex-key = Christiansen2014]
  131. Edmund S.L. Lam and Iliano Cervesato. Optimized Compilation of Multiset Rewriting with Comprehensions, pages 19-38. Springer International Publishing, Cham, 2014. ISBN: 978-3-319-12736-1. [WWW] [doi:10.1007/978-3-319-12736-1_2] [bibtex-key = Lam2014]
  132. Frédéric Lardeux and Eric Monfroy. From Declarative Set Constraint Models to ``Good'' SAT Instances, pages 76-87. Springer International Publishing, Cham, 2014. ISBN: 978-3-319-13770-4. [WWW] [doi:10.1007/978-3-319-13770-4_8] [bibtex-key = Lardeux2014]
  133. Marco Alberti, Marco Gavanelli, and Evelina Lamma. The CHR-based Implementation of the SCIFF Abductive System. Fundam. Inform., 124(4):365-381, 2013. [bibtex-key = DBLP:journals/fuin/AlbertiGL13]
  134. Maurizio Gabbrielli, Jacopo Mauro, and Maria Chiara Meo. The expressive power of CHR with priorities. Inf. Comput., 228:62-82, 2013. [bibtex-key = DBLP:journals/iandc/GabbrielliMM13]
  135. Maurizio Gabbrielli, Maria Chiara Meo, Paolo Tacchella, and Herbert Wiklicky. Unfolding for CHR programs. TPLP, 2013. Note: To appear. [PDF] [bibtex-key = gabbrielli_unfolding_tplp13]
  136. Marco Gavanelli and Toni Mancini. Automated reasoning. Intelligenza Artificiale, 7(2):113-124, 2013. [bibtex-key = gavanelli2013automated]
  137. Dragan Ivanovic. Implementing Constraint Handling Rules as a Domain-Specific Language Embedded in Java. CoRR, abs/1308.3939, 2013. [PDF] [bibtex-key = DBLP:journals/corr/Ivanovic13]
  138. Ester Martinez-Martin, Maria Teresa Escrig, and Angel P. del Pobil. A Qualitative Acceleration Model Based on Intervals. ADCAIJ: Advances in Distributed Computing and Artificial Intelligence Journal, 2(2), 2013. ISSN: 2255-2863. [WWW] Keyword(s): Model-based reasoning, Qualitative reasoning, Spatial reasoning.
    Abstract:
    On the way to autonomous service robots, spatial reasoning plays a main role since it properly deals with problems involving uncertainty. In particular, we are interested in knowing people's pose to avoid collisions. With that aim, in this paper, we present a qualitative acceleration model for robotic applications including representation, reasoning and a practical application.
    [bibtex-key = martinez2013qualitativeacceleration]
  139. Jacopo Mauro. Expressive power of Constraint Handling Rules extensions and fragments. Bulletin of EATCS, 3(111), 2013. [bibtex-key = mauro2013expressive]
  140. Carlos Olarte, Camilo Rueda, and Frank D. Valencia. Models and emerging trends of concurrent constraint programming. Constraints, 18(4):535-578, 2013. ISSN: 1572-9354. [WWW] [doi:10.1007/s10601-013-9145-3]
    Abstract:
    Concurrent Constraint Programming (CCP) has been used over the last two decades as an elegant and expressive model for concurrent systems. It models systems of agents communicating by posting and querying partial information, represented as constraints over the variables of the system. This covers a vast variety of systems as those arising in biological phenomena, reactive systems, net-centric computing and the advent of social networks and cloud computing. In this paper we survey the main applications, developments and current trends of CCP.
    [bibtex-key = Olarte2013]
  141. Elvira Albert, Marìa Garcìa de la Banda, Miguel Gómez-Zamalloa, José Miguel Rojas, and Peter J. Stuckey. A CLP heap solver for test case generation. In Evelina Lamma and Terrance Swift, editors, ICLP13l, volume 13(4--5) of TPLP, pages 721-735. CUP, August 2013. [PDF] [bibtex-key = albert_clp_heap_iclp13]
  142. Thom Frühwirth Jon Sneyers, Danny De Schreye. Probabilistic legal reasoning in CHRiSM. In Evelina Lamma and Terrance Swift, editors, ICLP13l, volume 13(4--5) of TPLP, pages 769-781. CUP, August 2013. [PDF] [bibtex-key = sneyers_legal_reasoning_iclp13]
  143. Amira Zaki, Thom Frühwirth, and Slim Abdennadher. Towards Inverse Execution of Constraint Handling Rules. In Evelina Lamma and Terrance Swift, editors, Technical Communications of the 29th Intl. Conf. on Logic Programming, volume 13(4--5), Online Supplement of TPLP. CUP, August 2013. [PDF] [bibtex-key = zaki_inverse_iclp13]
  144. Stefano Bistarelli, Fabio Martinelli, and Francesco Santini. A semiring-based framework for the deduction/abduction reasoning in access control with weighted credentials. Computers & Mathematics with Applications, (0):-, 2012. ISSN: 0898-1221. [WWW] [doi:10.1016/j.camwa.2011.12.017] Keyword(s): abduction, applications. [bibtex-key = Bistarelli2012]
  145. Stefano Bistarelli, Fabio Martinelli, and Francesco Santini. A semiring-based framework for the deduction/abduction reasoning in access control with weighted credentials. Computers & Mathematics with Applications, 64(4):447-462, 2012. [bibtex-key = DBLP:journals/cma/BistarelliMS12]
  146. Ruoyu Chen, Lejian Liao, and Zhi Fang. A Virtual Organization Model Based on Semantic Web Services and Its Application in Supply Chain for Agricultural Product. Advances in Control and Communication, 2012. [bibtex-key = chen_acc12]
  147. Gregory J. Duck. SMCHR: Satisfiability Modulo Constraint Handling Rules. CoRR, abs/1210.5307, 2012. [bibtex-key = DBLP:journals/corr/abs-1210-5307]
  148. Rémy Haemmerlé. Diagrammatic Confluence for Constraint Handling Rules. TPLP, 12(4-5):737-753, September 2012. ISSN: 1471-0684. [WWW] [doi:10.1017/S1471068412000270] Keyword(s): confluence. [bibtex-key = HaemmerlE:2012:DCC:2431176.2431194]
  149. Thomas König and Petra Hofstedt. Constraint-basierte Programmiersprachen. KI-Künstliche Intelligenz, 26(1):47-54, 2012. [bibtex-key = konig2012constraint]
  150. Cleyton Rodrigues, Ryan Ribeiro de Azevedo, Fred Freitas, and Eric Dantas. LSVF: a New Search Heuristic to Reduce the Backtracking Calls for Solving Constraint Satisfaction Problem. (IJARAI) International Journal of Advanced Research in Artificial Intelligence, 1(9):20-25, 2012. [bibtex-key = rodrigues2012]
  151. Kazunori Ueda and Seiji Ogawa. HyperLMNtal: An Extension of a Hierarchical Graph Rewriting Model. KI - Künstliche Intelligenz, pp 1-10, 2012. ISSN: 0933-1875. [WWW] Keyword(s): related formalisms. [bibtex-key = ueda_hyperLMNtal_KI12]
  152. Todd J. Green, Molham Aref, and Grigoris Karvounarakis. LogicBlox, Platform and Language: A Tutorial, pages 1-8. Springer Berlin Heidelberg, Berlin, Heidelberg, 2012. ISBN: 978-3-642-32925-8. [WWW] [doi:10.1007/978-3-642-32925-8_1] [bibtex-key = Green2012]
  153. Matje van de Camp and Henning Christiansen. Resolving relative time expressions in Dutch text with Constraint Handling Rules, pages 74-85. University of Orléans, 2012. [bibtex-key = 0231bfd0e10f4e06a72a33f7be26e0b4]
  154. M. Alberti, M. Gavanelli, and E. Lamma. Deon+: Abduction and Constraints for Normative Reasoning. In Alexander Artikis, Robert Craven, Nihan Kesim, Babak Sadighi, and Kostas Stathis, editors, Festschrift of Marek Sergot. Springer, 2012. [bibtex-key = alberti_deonplus_12]
  155. Stefano Bistarelli, Fabio Martinelli, Francesco Roperti, and Francesco Santini. Negotiation of Weighted RTML Credentials on Mobile Devices. In Marco De Marco, Dov Te'eni, Valentina Albano, and Stefano Za, editors, Information Systems: Crossroads for Organization, Management, Accounting and Engineering, pages 429-438. Physica-Verlag HD, 2012. ISBN: 978-3-7908-2788-0. [WWW] [doi:10.1007/978-3-7908-2789-7_47] [bibtex-key = Bistarelli-Martinelli-2012]
  156. Marco Alberti, Marco Gavanelli, Evelina Lamma, Fabrizio Riguzzi, and Sergio Storari. Learning specifications of interaction protocols and business processes and proving their properties. Intelligenza artificiale, 5(1):71-75, February 2011. ISSN: 1724-8035. [PDF] [doi:10.3233/IA-2011-0006]
    Abstract:
    In this paper, we overview our recent research activity concerning the induction of Logic Programming specifications, and the proof of their properties via Abductive Logic Programming. Both the inductive and abductive tools here briefly described have been applied to respectively learn and verify (properties of) interaction protocols in multi-agent systems, Web service choreographies, careflows and business processes.
    [bibtex-key = AlbGavLam10-IA-IJ]
  157. A.M. Cheadle, W. Harvey, A.J. Sadler, J. Schimpf, K. Shen, and M.G. Wallace. ECL$^i$PS$^e$: A Tutorial Introduction. 2011. Keyword(s): tutorial. [bibtex-key = cheadle2011tutorial]
  158. János Csorba, Zsolt Zombori, and Péter Szeredi. Using Constraint Handling Rules to Provide Static Type Analysis for the Q Functional Language. CoRR, abs/1112.3784, 2011. [bibtex-key = DBLP:journals/corr/abs-1112-3784]
  159. Gregory J. Duck, Joxan Jaffar, and Nicolas Koh. A Symbolic Execution Framework with Explicit Heaps and Separation. 2011. [bibtex-key = id9]
  160. Andrea Triossi. Hardware Execution of Constraint Handling Rules. PhD Thesis, 2011. [bibtex-key = triossi_phd11]
  161. Veronica Dahl. Informing Datalog through Language Intelligence - A Personal Perspective. In Oege de Moor, Georg Gottlob, Tim Furche, and Andrew Sellers, editors, Datalog Reloaded, volume 6702 of Lecture Notes in Computer Science, pages 161-180. Springer Berlin / Heidelberg, 2011. ISBN: 978-3-642-24205-2. [WWW] Keyword(s): linguistics. [bibtex-key = dahl_informing_datalog_2011]
  162. Veronica Dahl, Baohua Gu, and Erez Maharask. In Gemma Bel-Enguix and M. Dolores Jimenez-Lopez, editors, Bio-Inspired Models for Natural and Formal Languages, pages 205ff. Cambridge Scholars Publishing, April 2011. [bibtex-key = title={ModelingConceptsandRelationsthroughPropertyGrammars}]
  163. Veronica Dahl and Erez Maharask. In Gemma Bel-Enguix and M. Dolores Jimenez-Lopez, editors, Bio-Inspired Models for Natural and Formal Languages, pages 259ff. Cambridge Scholars Publishing, April 2011. [bibtex-key = title={Synalysis-aDualProcessingSchemeforBothHumanandBiologicalLanguages}]
  164. Rémy Haemmerlé. (Co-)Inductive semantics for Constraint Handling Rules. In John Gallagher and Michael Gelfond, editors, ICLP11l, volume 11(4--5) of TPLP, pages 593-609. CUP, July 2011. [doi:10.1017/S1471068411000196] Keyword(s): semantics, termination.
    Abstract:
    In this paper, we address the problem of defining a fixpoint semantics for Constraint Handling Rules (CHR) that captures the behavior of both simplification and propagation rules in a sound and complete way with respect to their declarative semantics. Firstly, we show that the logical reading of states with respect to a set of simplification rules can be characterized by a least fixpoint over the transition system generated by the abstract operational semantics of CHR. Similarly, we demonstrate that the logical reading of states with respect to a set of propagation rules can be characterized by a greatest fixpoint. Then, in order to take advantage of both types of rules without losing fixpoint characterization, we present an operational semantics with persistent. We finally establish that this semantics can be characterized by two nested fixpoints, and we show the resulting language is an elegant framework to program using coinductive reasoning
    [bibtex-key = haemmerle2011coinductive]
  165. Rémy Haemmerlé. Observational equivalences for linear logic concurrent constraint languages. In John Gallagher and Michael Gelfond, editors, ICLP11l, volume 11(4--5) of TPLP, pages 469-485. CUP, July 2011. [doi:10.1017/S1471068411000123] Keyword(s): linear logic, semantics, confluence, related formalisms.
    Abstract:
    Linear logic Concurrent Constraint programming (LCC) is an extension of concurrent constraint programming (CC), where the constraint system is based on Girard's linear logic instead of the classical logic. In this paper, we address the problem of program equivalence for this programming framework. For this purpose, we present a structural operational semantics for LCC based on a label transition system and investigate different notions of observational equivalences inspired by the state of art of process algebras. Then, we demonstrate that the asynchronous π-calculus can be viewed as simple syntactical restrictions of LCC. Finally, we show that LCC observational equivalences can be transposed straightforwardly to classical Concurrent Constraint languages and Constraint Handling Rules, and investigate the resulting equivalences.
    [bibtex-key = haemmerle2011equivalence]
  166. N. Berger. Modélisation et résolution en programmation par contraintes de problèmes mixtes continu/discret de satisfaction de contraintes et d'optimisation. October 2010. [bibtex-key = phDberger2010modélisation]
  167. S. Bistarelli, F. Martinelli, and F. Santini. A formal framework for trust policy negotiation in autonomic systems: abduction with soft constraints. Autonomic and Trusted Computing, pp 268-282, 2010. [bibtex-key = bistarelli2010formal]
  168. V. Dahl, M. Jiménez-López, and O. Perriquet. Poetic RNA: Adapting RNA Design Methods to the Analysis of Poetry. Trends in Practical Applications of Agents and Multiagent Systems, pp 403-410, 2010. [bibtex-key = dahl2010poetic]
  169. P. Deransart. Conception de traces et applications (vers une méta-théorie des traces)‘‘document de travail’’8 février 2010. 2010. [bibtex-key = deransart2010conception]
  170. M. Falda. Spatial Reasoning with Integrated Qualitative-Metric Fuzzy Constraint Networks. Journal of Universal Computer Science, 16(11):1390-1409, 2010. [bibtex-key = falda2010spatial]
  171. M. Gavanelli and F. Rossi. Constraint logic programming. A 25-year perspective on logic programming, pp 64-86, 2010. [bibtex-key = gavanelli2010constraint]
  172. G. Jerke, J. Lienig, and J.B. Freuer. Constraint-Driven Design Methodology: A Path to Analog Design Automation. Analog Layout Synthesis: A Survey of Topological Approaches, pp 269, 2010. [bibtex-key = jerke2010constraint]
  173. Y.S. Liu, H.J. Zhu, M. Zhu, and Y.Q. Xu. Research and implementation on negative disjunction constraints in FLUX. Jisuanji Yingyong Yanjiu, 27(8):2980-2983, 2010. Keyword(s): FLUX. [bibtex-key = liu2010research]
  174. M. Montali. Proof Procedures. Specification and Verification of Declarative Open Interaction Models, pp 201-227, 2010. [bibtex-key = montali2010proof]
  175. M. Montali, P. Torroni, F. Chesani, P. Mello, M. Alberti, and E. Lamma. Abductive logic programming as an effective technology for the static verification of declarative business processes. Fundamenta Informaticae, 102(3):325-361, 2010. [bibtex-key = montali2010abductive]
  176. J. Oliveira and E. Carrapatoso. Evaluating the Adaptation of Multimedia Services Using a Constraints-Based Approach. Mobile Multimedia Processing, pp 70-88, 2010. [bibtex-key = oliveira2010evaluating]
  177. Frank Raiser and Thom Frühwirth. Analyzing Graph Transformation Systems through Constraint Handling Rules. TPLP, 2010. Note: To appear. Keyword(s): Graph Transformation Systems, related formalisms.
    Abstract:
    Abstract: Graph transformation systems (GTS) and constraint handling rules (CHR) are non-deterministic rule-based state transition systems. CHR is well-known for its powerful confluence and program equivalence analyses, for which we provide the basis in this work to apply them to GTS. We give a sound and complete embedding of GTS in CHR, investigate confluence of an embedded GTS, and provide a program equivalence analysis for GTS via the embedding. The results confirm the suitability of CHR-based program analyses for other formalisms embedded in CHR.
    [bibtex-key = raiser_gts_tplp10]
  178. I. Salomie, V.R. Chifu, I. Harsa, and M. Gherga. Web service composition using fluent calculus. International Journal of Metadata, Semantics and Ontologies, 5(3):238-250, 2010. [bibtex-key = salomie2010web]
  179. Z. Shan, C. Jin-yi, and WAN Jun-peng. QSRM: An Implementation Method for Qualitative Spatial Reasoning with Constraint Handling Rules. Journal of Changshu Institute of Technology, pp 90-94, 2010. [bibtex-key = shan2010qsrm]
  180. Jon Sneyers, Peter Van Weert, Tom Schrijvers, and Leslie De Koninck. As Time Goes By: Constraint Handling Rules -- A Survey of CHR Research between 1998 and 2007. TPLP, 10(1):1-47, 2010. [PDF] [doi:10.1017/S1471068409990123] Keyword(s): survey.
    Abstract:
    Constraint Handling Rules (CHR) is a high-level programming language based on multiheaded multiset rewrite rules. Originally designed for writing user-defined constraint solvers, it is now recognized as an elegant general purpose language. CHR-related research has surged during the decade following the previous survey by Fr{\"u}hwirth (\emph{J. Logic Programming, Special Issue on Constraint Logic Programming}, 1998, vol. 37, nos. 1--3, pp. 95--138). Covering more than 180 publications, this new survey provides an overview of recent results in a wide range of research areas, from semantics and analysis to systems, extensions and applications.
    [bibtex-key = chr_survey_tplp10]
  181. Peter Van Weert. Efficient Lazy Evaluation of Rule-Based Programs. IEEE Transactions on Knowledge and Data Engineering, 22(11):1521-1534, November 2010. [doi:10.1109/TKDE.2009.208] Keyword(s): implementation, optimizing compilation. [bibtex-key = vanweert_lazy_evaluation_tkde10]
  182. D. Vytiniotis, S.P. Jones, T. Schrijvers, and M. Sulzmann. OutsideIn (X) Modular type inference with local assumptions. 2010. [bibtex-key = vytiniotis2010outsidein]
  183. Bernhard Aichernig. A Systematic Introduction to Mutation Testing in Unifying Theories of Programming. In Paulo Borba, Ana Cavalcanti, Augusto Sampaio, and Jim Woodcook, editors, Testing Techniques in Software Engineering, volume 6153 of LNCS, pages 243-287. SV, 2010. [doi:10.1007/978-3-642-14335-9_8] Keyword(s): applications, testing.
    Abstract:
    This chapter presents a theory of testing that integrates into Hoare and He’s Unifying Theories of Programming (UTP). We give test cases a denotational semantics by viewing them as specification predicates. This reformulation of test cases allows for relating test cases via refinement to specifications and programs. Having such a refinement order that integrates test cases, we develop a testing theory for fault-based testing. As discussed in Chapter 1, fault-based testing uses test data designed to demonstrate the absence of a set of pre-specified faults. A well-known fault-based technique is mutation testing. In mutation testing, first, faults are injected into a program by altering (mutating) its source code. Then, test cases that can detect these errors are designed. The assumption is that other faults will be caught, too. In this chapter, we apply the mutation technique to both specifications and programs.
    [bibtex-key = aichernig_mutation_testing_2010]
  184. Hariolf Betz, Frank Raiser, and Thom Frühwirth. A Complete and Terminating Execution Model for Constraint Handling Rules. In Manuel Hermenegildo and Torsten Schaub, editors, ICLP10l, volume 10(4--6) of TPLP, pages 597-610. CUP, July 2010. [doi:10.1017/S147106841000030X] Keyword(s): semantics, termination. [bibtex-key = betz_raiser_fru_execution_model_iclp10]
  185. Stefano Bistarelli, Fabio Martinelli, and Francesco Santini. A formal framework for trust policy negotiation in autonomic systems: abduction with soft constraints. In Autonomic and Trusted Computing, pages 268-282. Springer, 2010. [bibtex-key = bistarelli2010formal]
  186. Maurizio Gabbrielli, Jacopo Mauro, Maria Chiara Meo, and Jon Sneyers. Decidability properties for fragments of CHR. In Manuel Hermenegildo and Torsten Schaub, editors, ICLP10l, volume 10(4--6) of TPLP, pages 611-626. CUP, July 2010. [doi:10.1017/S1471068410000311] Keyword(s): computability. [bibtex-key = gabbrielli_mauro_meo_sneyers_dedidability_iclp10]
  187. Jon Sneyers, Wannes Meert, Joost Vennekens, Yoshitaka Kameya, and Taisuke Sato. CHR(PRISM)-based Probabilistic Logic Learning. In Manuel Hermenegildo and Torsten Schaub, editors, ICLP10l, volume 10(4--6) of TPLP, pages 433-447. CUP, July 2010. [doi:10.1017/S1471068410000207] Keyword(s): probabilistic CHR, CHRiSM, extensions. [bibtex-key = sneyers_et_al_chrprism_iclp10]
  188. Henning Christiansen. Executable specifications for hypotheses-based reasoning with Prolog and Constraint Handling Rules. J. of Applied Logic, 7(3):341-362, September 2009. [doi:10.1016/j.jal.2008.10.004] Keyword(s): abduction. [bibtex-key = christ_hypoth_based_reasoning_jal09]
  189. Leslie De Koninck. Logical Algorithms meets CHR: A meta-complexity result for Constraint Handling Rules with rule priorities. TPLP, 9(2):165-212, March 2009. [doi:10.1017/S1471068409003664] Keyword(s): priorities, related formalisms, complexity.
    Abstract:
    This paper investigates the relationship between the Logical Algorithms language (LA) of Ganzinger and McAllester and Constraint Handling Rules (CHR). We present a translation schema from LA to CHR-rp: CHR with rule priorities, and show that the meta-complexity theorem for LA can be applied to a subset of CHR-rp via inverse translation. Inspired by the high-level implementation proposal for Logical Algorithm by Ganzinger and McAllester and based on a new scheduling algorithm, we propose an alternative implementation for CHR-rp that gives strong complexity guarantees and results in a new and accurate meta-complexity theorem for CHR-rp. It is furthermore shown that the translation from Logical Algorithms to CHR-rp combined with the new CHR-rp implementation, satisfies the required complexity for the Logical Algorithms meta-complexity result to hold.
    [bibtex-key = dekoninck_la_meets_chr_tplp09]
  190. Maurizio Gabbrielli and Maria Chiara Meo. A compositional semantics for CHR. TOCL, 10(2):1-36, February 2009. [doi:10.1145/1462179.1462183] Keyword(s): semantics.
    Abstract:
    Constraint Handling Rules (CHR) is a committed-choice declarative language which has been designed for writing constraint solvers. A CHR program consists of multiheaded guarded rules which allow to rewrite constraints into simpler ones until a solved form is reached. CHR has received considerable attention, both from the practical and from the theoretical side. Nevertheless, due the use of multiheaded clauses, there are several aspects of the CHR semantics which have not been clarified yet. In particular, no compositional semantics for CHR has been defined so far. In this article we introduce a fix-point semantics which characterizes the input/output behavior of a CHR program and which is and-compositional, that is, which allows to retrieve the semantics of a conjunctive query from the semantics of its components. Such a semantics can be used as a basis to define incremental and modular analysis and verification tools.
    [bibtex-key = gabbr_meo_compos_semantics_tocl09]
  191. Edmund S.L. Lam and Martin Sulzmann. Concurrent goal-based execution of Constraint Handling Rules. TPLP, 11:841-879, 2009. [POSTSCRIPT] Keyword(s): parallelism.
    Abstract:
    We introduce a systematic, concurrent execution scheme for Constraint Handling Rules (CHR) based on a previously proposed goal-based CHR semantics. We establish strong correspondence results to the abstract CHR semantics, thus guaranteeing that any answer in the concurrent, goal-based CHR semantics is reproducible in the abstract CHR semantics. Our work provides the foundation to obtain efficient, parallel CHR execution schemes.
    [bibtex-key = lam_sulzmann_conc_goal_based_tplp09]
  192. Jon Sneyers, Tom Schrijvers, and Bart Demoen. The Computational Power and Complexity of Constraint Handling Rules. TOPLAS, 31(2), February 2009. [doi:10.1145/1462166.1462169] Keyword(s): complexity, computability. [bibtex-key = sney_schr_demoen_chr_complexity_toplas09]
  193. Hongwei Zhu and Stuart E. Madnick. Reconciliation of temporal semantic heterogeneity in evolving information systems. Ingénierie des Systèmes d'Information, 14(6):59-74, 2009. [bibtex-key = zhu_madnick_09]
  194. Bernhard K. Aichernig and He Jifeng. Mutation testing in UTP. Formal Aspects of Computing, 21(1--2):33-64, February 2008. [doi:10.1007/s00165-008-0083-6] Keyword(s): testing.
    Abstract:
    This paper presents a theory of testing that integrates into Hoare and He’s Unifying Theory of Programming (UTP). We give test cases a denotational semantics by viewing them as specification predicates. This reformulation of test cases allows for relating test cases via refinement to specifications and programs. Having such a refinement order that integrates test cases, we develop a testing theory for fault-based testing. Fault-based testing uses test data designed to demonstrate the absence of a set of pre-specified faults. A well-known fault-based technique is mutation testing. In mutation testing, first, faults are injected into a program by altering (mutating) its source code. Then, test cases that can detect these errors are designed. The assumption is that other faults will be caught, too. In this paper, we apply the mutation technique to both, specifications and programs. Using our theory of testing, two new test case generation laws for detecting injected (anticipated) faults are presented: one is based on the semantic level of UTP design predicates, the other on the algebraic properties of a small programming language.
    [bibtex-key = mutation_testing_fac08]
  195. Khalil Djelloul, Dao Thi-Bich-Hanh, and Thom Frühwirth. Theory of finite or infinite trees revisited. TPLP, 8(4):431-489, 2008. [doi:10.1017/S1471068407003171]
    Abstract:
    We present in this paper a first-order axiomatization of an extended theory $T$ of finite or infinite trees, built on a signature containing an infinite set of function symbols and a relation $finite(t)$, which enables to distinguish between finite and infinite trees. We show that $T$ has at least one model and prove its completeness by giving not only a decision procedure, but a full first-order constraint solver that gives clear and explicit solutions for any first-order constraint satisfaction problem in $T$. The solver is given in the form of 16 rewriting rules that transform any first-order constraint $\Phi$ into an equivalent disjunction $/phi$ of simple formulas such that $\phi$ is either the formula $true$ or the formula $false$ or a formula having at least one free variable, being equivalent neither to $true$ nor to $false$ and where the solutions of the free variables are expressed in a clear and explicit way. The correctness of our rules implies the completeness of $T$. We also describe an implementation of our algorithm in CHR (Constraint Handling Rules) and compare the performance with an implementation in C++ and that of a recent decision procedure for decomposable theories.
    [bibtex-key = djelloul_et_al_trees_revisited_tplp08]
  196. Tom Schrijvers, Bart Demoen, and David S. Warren. TCHR: a framework for tabled CLP. TPLP, 8(4):491-526, July 2008. [doi:10.1017/S147106840800327X] Keyword(s): implementation.
    Abstract:
    Tabled Constraint Logic Programming is a powerful execution mechanism for dealing with Constraint Logic Programming without worrying about fixpoint computation. Various applications, e.g. in the fields of program analysis and model checking, have been proposed. Unfortunately, a high-level system for developing new applications is lacking, and programmers are forced to resort to complicated ad hoc solutions. This papers presents TCHR, a high-level framework for tabled Constraint Logic Programming. It integrates in a light-weight manner Constraint Handling Rules (CHR), a high-level language for constraint solvers, with tabled Logic Programming. The framework is easily instantiated with new application-specific constraint domains. Various high-level operations can be instantiated to control performance. In particular, we propose a novel, generalized technique for compacting answer sets.
    [bibtex-key = schr_warren_tchr_tplp08]
  197. Martin Sulzmann and Peter J. Stuckey. HM(X) Type Inference is CLP(X) Solving. Journal of Functional Programming, 18(2):251-283, 2008. [doi:10.1017/S0956796807006569] Keyword(s): type systems.
    Abstract:
    The HM(X) system is a generalization of the Hindley/Milner system parameterized in the constraint domain X. Type inference is performed by generating constraints out of the program text, which are then solved by the domain-specific constraint solver X. The solver has to be invoked at the latest when type inference reaches a let node so that we can build a polymorphic type. A typical example of such an inference approach is Milner's algorithm W. We formalize an inference approach where the HM(X) type inference problem is first mapped to a CLP(X) program. The actual type inference is achieved by executing the CLP(X) program. Such an inference approach supports the uniform construction of type inference algorithms and has important practical consequences when it comes to reporting type errors. The CLP(X) style inference system, where X is defined by Constraint Handling Rules, is implemented as part of the Chameleon system.
    [bibtex-key = sulzm_stuckey_hmx_is_clpx_jfp08]
  198. Hongwei Zhu, Stuart E. Madnick, and Michael D. Siegel. Enabling global price comparison through semantic integration of web data. IJEB, 6(4):319-341, 2008. [bibtex-key = zhu_madnick_siegel_IJEB08]
  199. Henning Christiansen. Implementing Probabilistic Abductive Logic Programming with Constraint Handling Rules. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 85-118. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_5] Keyword(s): abduction, probabilistic CHR. [bibtex-key = christiansen_prob_abd_lp_lnai08]
  200. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. A Flexible Search Framework for CHR. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 16-47. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_2] Keyword(s): disjunction, search. [bibtex-key = dekoninck_et_al_flexible_search_lnai08]
  201. Thom Frühwirth. Welcome to Constraint Handling Rules. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 1-15. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_1] Keyword(s): tutorial. [bibtex-key = fru_welcome_lnai08]
  202. Maurizio Gabbrielli, Maria Chiara Meo, and Paolo Tacchella. A Compositional Semantics for CHR with Propagation Rules. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 119-160. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_6] Keyword(s): semantics. [bibtex-key = gabbrielli_meo_tacchella_comp_sem_lnai08]
  203. Jon Sneyers, Tom Schrijvers, and Bart Demoen. Guard Reasoning in the Refined Operational Semantics of CHR. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 213-244. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_8] Keyword(s): implementation, optimizing compilation. [bibtex-key = sneyers_et_al_guard_reasoning_lnai08]
  204. Ingi Sobhi, Slim Abdennadher, and Hariolf Betz. Constructing Rule-Based Solvers for Intentionally-Defined Constraints. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 70-84. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_4] Keyword(s): program generation. [bibtex-key = sobhi_abd_betz_intentionally_def_constraints_lnai08]
  205. Peter Van Weert, Pieter Wuille, Tom Schrijvers, and Bart Demoen. CHR for Imperative Host Languages. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 161-212. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_7] Keyword(s): implementation, Java.
    Abstract:
    In this paper, we address the different conceptual and technical difficulties encountered when embedding CHR into an imperative host language. We argue that a tight, natural integration leads to a powerful programming language extension, intuitive to both CHR and imperative programmers. We show how to compile CHR to highly optimized imperative code. To this end, we first review the well-established CHR compilation scheme, and survey the large body of possible optimizations. We then show that this scheme, when used for compilation to imperative target languages, leads to stack overflows. We therefore introduce new optimizations that considerably improve the performance of recursive CHR programs. Rules written using tail calls are even guaranteed to run in constant space. We implemented systems for both Java and C, following the language design principles and compilation scheme presented in this paper, and show that our implementations outperform other state-of-the-art CHR compilers by several orders of magnitude.
    [bibtex-key = vanweert_wuille_et_al_chr_imperative_lnai08]
  206. Armin Wolf, Jacques Robin, and Jairson Vitorino. Adaptive CHR meets CHR$^\vee$: An Extended Refined Operational Semantics for CHR$^\vee$ Based on Justifications. In Tom Schrijvers and Thom Frühwirth, editors, Constraint Handling Rules --- Current Research Topics, volume 5388 of LNAI, pages 48-69. SV, December 2008. [WWW] [doi:10.1007/978-3-540-92243-8_3] Keyword(s): disjunction, search, semantics. [bibtex-key = wolf_robin_vitorino_chrv_semantics_lnai08]
  207. Marco Alberti, Federico Chesani, Davide Daolio, Marco Gavanelli, Evelina Lamma, Paola Mello, and Paolo Torroni. Specification and Verification of Agent Interaction Protocols in a Logic-based System. Scalable Computing: Practice and Experience, 8(1):1-13, March 2007.
    Abstract:
    A number of information systems can be described as a set of interacting entities, which must follow interaction protocols. These protocols determine the behaviour and the properties of the overall system, hence it is of the uttermost importance that the entities behave in a conformant manner. A typical case is that of multi-agent systems, composed of a plurality of agents without a centralized control. Compliance to protocols can be hardwired in agent programs; however, this requires that only ``certified'' agents interact. In open systems, composed of autonomous and heterogeneous entities whose internal structure is, in general, not accessible (open agent societies being, again, a prominent example) interaction protocols should be specified in terms of the extit{observable} behaviour, and compliance should be verified by an external entity. In this paper, we propose a Java-Prolog-CHR system for verification of compliance of computational entities to protocols specified in a logic-based formalism ( extit{Social Integrity Constraints}). We also show the application of the formalism and the system to the specification and verification of three different scenarios: two specifications show the feasibility of our approach in the context of Multi Agent Systems (FIPA Contract-Net Protocol and Semi-Open societies), while a third specification applies to the specification of a lower level protocol (Open-Connection phase of the TCP protocol).
    [bibtex-key = alberti_et_al_agent_interaction_scpe07]
  208. Mathieu Boespflug. TaiChi:how to check your types with serenity. The Monad.Reader, 9:17-31, November 2007. Keyword(s): type systems. [bibtex-key = boespflug_taichi_monadreader07]
  209. Jacques Robin, Jairson Vitorino, and Armin Wolf. Constraint Programming Architectures: Review and a New Proposal. j-jucs, 13(6):701-720, 2007. [WWW]
    Abstract:
    Most automated reasoning tasks with prac tical applications can be automatically reformulated into a constraint solving task. A constraint programming platform can thus act as a unique, underlying engine to be reused for mu ltiple automated reasoning tasks in intelligent agents and systems. We identify six key requirements for such platform: expressive task modeling language, rapid solving method custom ization and combination, adaptive solving method, user-friendly solution explanation, efficient execution, and seamless integration within larger systems and practical applications. We then propose a novel, model-driven, component and rule-based architecture for such a platform that better satisfies as a whole this set of requirements than those of currently available platforms.
    [bibtex-key = robin_vitorino_wolf_CPA_proposal_jucs07]
  210. Beata Sarna-Starosta, R. E. Kurt Stirewalt, and Laura K. Dillon. A Model-Based Design-for-Verification Approach to Checking for Deadlock in Multi-Threaded Applications. Intl. Journal of Softw. Engin. and Knowl. Engin., 17(2):207-230, 2007. [doi:10.1142/S0218194007003197] Keyword(s): applications, testing.
    Abstract:
    This paper explores an approach to design for verification in systems built atop a middleware framework which separates synchronization concerns from the ``core-functional logic'' of a program. The framework is based on a language-independent compositional model of synchronization contracts, called Szumo, which integrates well with popular OO design artifacts and provides strong guarantees of non-interference for a class of strictly exclusive systems. An approach for extracting models from Szumo design artifacts and analyzing the generated models to detect deadlocks is described. A key decision was to use Constraint Handling Rules to express the semantics of synchronization contracts, which allowed a transparent model of the implementation logic.
    [bibtex-key = ss_stirewalt_dillon_checking_deadlock_ijseke07]
  211. Martin Sulzmann, Gregory J. Duck, Simon Peyton-Jones, and Peter J. Stuckey. Understanding functional dependencies via Constraint Handling Rules. J. Functional Prog., 17(1):83-129, 2007. [doi:10.1017/S0956796806006137] Keyword(s): type systems. [bibtex-key = sulz_duck_peyton_stuck_func_dep_via_chr_fp07]
  212. Marco Alberti, Marco Gavanelli, Evelina Lamma, Federico Chesani, Paola Mello, and Paolo Torroni. Compliance Verification of Agent Interaction: a Logic-based Software Tool. Applied Artificial Intelligence, 20(2--4):133-157, 2006. [bibtex-key = alberti_et_al_compliance_agents_tool_aai06]
  213. Maryam Bavarian and Verónica Dahl. Constraint Based Methods for Biological Sequence Analysis. j-jucs, 12(11):1500-1520, 2006. [WWW] Keyword(s): applications.
    Abstract:
    The need for processing biological information is rapidly growing, owing to the masses of new information in digital form being produced at this time. Old methodologies for processing it can no longer keep up with this rate of growth. The methods of Artificial Intelligence (AI) in general and of language processing in particular can offer much towards solving this problem. However, interdisciplinary research between language processing and molecular biology is not yet widespread, partly because of the effort needed for each specialist to understand the other one's jargon. We argue that by looking at the problems of molecular biology from a language processing perspective, and using constraint based logic methodologies we can shorten the gap and make interdisciplinary collaborations more effective. We shall discuss several sequence analysis problems in terms of constraint based formalisms such Concept Formation Rules, Constraint Handling Rules (CHR) and their grammatical counterpart, CHRG. We postulate that genetic structure analysis can also benefit from these methods, for instance to reconstruct from a given RNA secondary structure, a nucleotide sequence that folds into it. Our proposed methodologies lend direct executability to high level descriptions of the problems at hand and thus contribute to rapid while efficient prototyping.
    [bibtex-key = bavarian_dahl_bio_seq_analysis_jucs06]
  214. Wei-Ngan Chin, Florin Craciun, Siau-Cheng Khoo, and Corneliu Popeea. A flow-based approach for variant parametric types. SIGPLAN Not., 41(10):273-290, 2006. Keyword(s): type systems. [bibtex-key = chin_et_al_florin_sigplan06]
  215. Tom Schrijvers and Thom Frühwirth. Optimal union-find in Constraint Handling Rules. TPLP, 6(1--2):213-224, 2006. ISSN: 1471-0684. [doi:10.1017/S1471068405002541] Keyword(s): algorithms. [bibtex-key = schr_fru_opt_union_find_tplp06]
  216. Yoshinori Shigeta, Kiyoshi Akama, Hiroshi Mabuchi, and Hidekatsu Koike. Converting Constraint Handling Rules to Equivalent Transformation Rules. JACIII, 10(3):339-348, 2006. Keyword(s): related formalisms. [bibtex-key = shigeta_akama_mabuchi_koike_chr_to_etr_jaciii06]
  217. Peter J. Stuckey and Martin Sulzmann. A theory of overloading. TOPLAS, 27(6):1216-1269, 2005. ISSN: 0164-0925. Keyword(s): type systems. [bibtex-key = stuck_sulz_theory_of_overloading_toplas05]
  218. Slim Abdennadher and Christophe Rigotti. Automatic generation of CHR constraint solvers. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 403-418. CUP, July 2005. [doi:10.1017/S1471068405002371] Keyword(s): program generation. [bibtex-key = abd_rigotti_automatic_generation_tplp05]
  219. Marco Alberti, Marco Gavanelli, Evelina Lamma, Paola Mello, and Michela Milano. A CHR-based implementation of known arc-consistency. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 419-440. CUP, July 2005. [doi:10.1017/S147106840500236X] [bibtex-key = alberti_et_al_chr_implementation_of_arc_consistency_tplp05]
  220. Sebastian Brand and Krzysztof R. Apt. Schedulers and Redundancy for a Class of Constraint Propagation Rules. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 441-465. CUP, July 2005. [doi:10.1017/S1471068405002401] [bibtex-key = brand_apt_schedulers_redundancy_tplp05]
  221. Henning Christiansen. CHR grammars. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 467-501. CUP, July 2005. [doi:10.1017/S1471068405002395] Keyword(s): applications, linguistics. [bibtex-key = christ_chr_grammars_tplp05]
  222. Christian Holzbaur, Marìa Garcìa de la Banda, Peter J. Stuckey, and Gregory J. Duck. Optimizing compilation of Constraint Handling Rules in HAL. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 503-531. CUP, July 2005. [doi:10.1017/S1471068405002413] Keyword(s): implementation, optimizing compilation. [bibtex-key = holz_garc_stuck_duck_opt_comp_chr_hal_tplp05]
  223. Michael Thielscher. FLUX: A Logic Programming Method for Reasoning Agents. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 533-565. CUP, July 2005. [doi:10.1017/S1471068405002358] Keyword(s): FLUX. [bibtex-key = thielscher_flux_tplp05]
  224. Armin Wolf. Intelligent search strategies based on adaptive Constraint Handling Rules. In Slim Abdennadher, Thom Frühwirth, and Christian Holzbaur, editors, Special Issue on Constraint Handling Rules, volume 5(4--5) of Theory and Practice of Logic Programming, pages 567-594. CUP, July 2005. [doi:10.1017/S1471068405002383] [bibtex-key = wolf_intelligent_search_tplp05]
  225. Slim Abdennadher and Christophe Rigotti. Automatic generation of rule-based constraint solvers over finite domains. TOCL, 5(2):177-205, 2004. ISSN: 1529-3785. Keyword(s): program generation. [bibtex-key = abd_rigo_automatic_gen_of_solvers_tocl04]
  226. Stefano Bistarelli, Thom Frühwirth, Michael Marte, and Francesca Rossi. Soft Constraint Propagation and Solving in Constraint Handling Rules. Computational Intelligence: Special Issue on Preferences in AI and CP, 20(2):287-307, May 2004. [bibtex-key = bistarelli_fru_marte_rossi_soft_constraint_propagation_CI04]
  227. Antonio J. Fernández and Patricia M. Hill. An interval constraint system for lattice domains. ACM Trans. Program. Lang. Syst., 26(1):1-46, 2004. ISSN: 0164-0925. [doi:10.1145/963778.963779] [bibtex-key = fern_hill_interval_constraint_system_toplas04]
  228. Alexander Pretschner, Heiko Lötzbeyer, and Jan Philipps. Model based testing in incremental system development. Journal of Systems and Software, 70(3):315-329, 2004. ISSN: 0164-1212. [doi:10.1016/S0164-1212(03)00076-1] Keyword(s): applications, testing.
    Abstract:
    The spiraling nature of evolutionary software development processes produces executable parts of the system at the end of each loop. It is argued that these parts should consist not only of programming language code, but of executable graphical system models. As a main benefit of the use of more abstract, yet formal, modeling languages, a method for model based test sequence generation for reactive systems on the grounds of Constraint Logic Programming as well as its implementation in the CASE tool AF is presented.
    [bibtex-key = pretschner_et_al_model_based_testing_jss04]
  229. Alexander Pretschner, Oscar Slotosch, Ernst Aiglstorfer, and Stefan Kriebel. Model-based testing for real. J. Software Tools for Technology Transfer (STTT), 5(2--3):140-157, 2004. Keyword(s): applications, testing. [bibtex-key = pretschner_et_al_model-based_testing_sttt04]
  230. Steve Barker and Peter J. Stuckey. Flexible access control policy specification with constraint logic programming. ACM Trans. Inf. Syst. Secur., 6(4):501-546, 2003. ISSN: 1094-9224. [doi:10.1145/950191.950194] [bibtex-key = barker_stuckey_access_control_tiss03]
  231. Lledó Museros Cabedo and Marìa Teresa Escrig. Modeling Motion by the Integration of Topology and Time. j-jucs, 9(9):1096-1122, 2003. [WWW]
    Abstract:
    A qualitative representational model and the corresponding reasoning process for integrating time and topological information is developed in this paper. In the calculus presented, topological information in function of the point of the time in which it is true is represented as an instance of the Constraint Satisfaction Problem. The resulting method can be applied to qualitative navigation of autonomous agents. The model presented in this paper will help us during the path planning task by describing the sequence of topological situations that the agent should find during its way to the target objective. A preliminary result of that application has been obtained by using qualitative representation of such spatial aspects for the autonomous simulated navigation of a Nomad-200 robot, on a structured environment of an easy corridor in a building.
    [bibtex-key = museros_escrig_modeling_motion_jucs03]
  232. Henning Christiansen and Verónica Dahl. Logic Grammars for Diagnosis and Repair. Intl. J. Artificial Intelligence Tools, 12(3):227-248, 2003. Keyword(s): applications, abduction. [bibtex-key = christ_dahl_diagnosis_and_repair_ijait03]
  233. Krzysztof R. Apt and Eric Monfroy. Constraint programming viewed as rule-based programming. TPLP, 1(6):713-750, 2001. ISSN: 1471-0684. [doi:10.1017/S1471068401000072] [bibtex-key = apt_monfroy_cp_viewed_as_rulebased_tplp01]
  234. Thom Frühwirth and Slim Abdennadher. The Munich Rent Advisor: A success for logic programming on the Internet. TPLP, 1(3):303-319, 2001. ISSN: 1471-0684. [doi:10.1017/S1471068401001181] Keyword(s): applications. [bibtex-key = fru_abd_munich_rent_advisor_tplp01]
  235. Marìa Teresa Escrig and Francisco Toledo. Autonomous robot navigation using human spatial concepts. Intl. Journal on Intelligent Systems, 15(3):165-196, February 2000.
    Abstract:
    With the aim of automatically reasoning with spatial aspects in a cognitive way, several qualitative models have been developed in recent years. However, there is no model to reason with several spatial aspects in a uniform way. Moreover, most of these models simplify spatial objects to points. In this paper we present the use of constraint logic programming instantiated to finite domains extended with constraint handling rules as a tool for successfully integrating the qualitative concepts of orientation, distance, and cardinal directions, using points as well as extended objects as a primitive of reasoning. The resulting model has been applied to build a demonstrator: a qualitative navigation simulator on the structured environment of our city.
    [bibtex-key = robot_nav_jis00]
  236. Thom Frühwirth and Pascal Brisset. Placing Base Stations in Wireless Indoor Communication Networks. IEEE Intelligent Systems and Their Applications, 15(1):49-53, 2000. Keyword(s): applications. [bibtex-key = fru_bri_base_wireless_ieee00]
  237. Slim Abdennadher and Michael Marte. University Course Timetabling Using Constraint Handling Rules.. In C. Holzbaur and Th. Frühwirth, editors, Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence, pages 311-325. Taylor & Francis, April 2000. [doi:10.1080/088395100117016] [bibtex-key = abd_marte_timetabling_chr_aai00]
  238. Henning Christiansen and Davide Martinenghi. Symbolic constraints for meta-logic programming. In C. Holzbaur and Th. Frühwirth, editors, Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence, pages 345-367. Taylor & Francis, April 2000. [doi:10.1080/088395100117034] [bibtex-key = christiansen_meta_logic_aai00]
  239. Christian Holzbaur and Thom Frühwirth. A Prolog Constraint Handling Rules Compiler and Runtime System.. In C. Holzbaur and Th. Frühwirth, editors, Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence, pages 369-388. Taylor & Francis, April 2000. [doi:10.1080/088395100117043] Keyword(s): implementation. [bibtex-key = holz_fru_prolog_chr_compiler_aai00]
  240. Christian Holzbaur and Thom Frühwirth. Selected recent project descriptions involving CHR. In C. Holzbaur and Th. Frühwirth, editors, Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence, pages 417-420. Taylor & Francis, April 2000. [doi:10.1080/088395100117061] [bibtex-key = holz_fru_recent_projects_aai00]
  241. Bernd Meyer. A Constraint-Based Framework for Diagrammatic Reasoning. In C. Holzbaur and Th. Frühwirth, editors, Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence, pages 327-344. Taylor & Francis, April 2000. [doi:10.1080/088395100117025] [bibtex-key = meyer_diagrammatic_reasoning_aai00]
  242. Armin Wolf, Thomas Gruenhagen, and Ulrich Geske. On Incremental Adaptation of CHR Derivations. In C. Holzbaur and Th. Frühwirth, editors, Special Issue on Constraint Handling Rules, volume 14(4) of Journal of Applied Artificial Intelligence, pages 389-416. Taylor & Francis, April 2000. [doi:10.1080/088395100117052] [bibtex-key = wolf_ea_incremental_adaptation_aai00]
  243. Slim Abdennadher, Thom Frühwirth, and Holger Meuss. Confluence and Semantics of Constraint Simplification Rules. Constraints, 4(2):133-165, 1999. ISSN: 1383-7133. [doi:10.1023/A:1009842826135] Keyword(s): confluence, semantics. [bibtex-key = abd_fru_meuss_confluence_semantics_csr_constr99]
  244. Mireille Ducassé. Opium: an extendable trace analyzer for Prolog. J. Logic Programming, 39(1--3):177-223, 1999. [bibtex-key = ducasse_opium_jlp99]
  245. Marìa Teresa Escrig and Francisco Toledo. A Framework Based on CLP Extended with CHRs for Reasoning with Qualitative Orientation and Positional Information. J. Visual Languages and Computing, 9(1):81-101, 1998. [bibtex-key = escrig_toledo_framework_qual_orientation_vlc98]
  246. Thom Frühwirth. Theory and Practice of Constraint Handling Rules. J. Logic Programming, Special Issue on Constraint Logic Programming, 37(1--3):95-138, 1998. [POSTSCRIPT] [doi:10.1016/S0743-1066(98)10005-5] Keyword(s): survey. [bibtex-key = fru_chr_overview_jlp98]
  247. Thom Frühwirth, Pascal Brisset, and Jörq-Rainer Molwitz. Planning Cordless Business Communication Systems. IEEE Intelligent Systems, 11(1):50-55, 1996. [doi:10.1109/64.482958]
    Abstract:
    People in their cars, people in the street, people at work, people at home--communicating through their mobile phones. Wireless communication might be the trend of the nineties, and it definitely means big business for the telecommunication industry. In Germany, for example, every third phone sold today is mobile. In the US, there will soon be 20 million subscribers to cellular phone services. In the second half of the nineties, 20% to 30% of phones sold worldwide are expected to be wireless . The introduction of a European standard for digital cordless telecommunication has made cordless local area networks possible. Mobile communication can come to company sites. No cabling is required, and the employees can be reached anytime at any place. However, planning wireless digital networks is quite different from planning traditional wire-based systems. The plan must account for the specifics of radio-wave propagation at the installation site. Computer-aided planning promises to ease some of the difficulties. In this article, we describe Popular (Planning of Picocellular Radio), a prototype tool resulting from a collaboration of industry and research institutions in Germany: the Siemens Research and Development Department, the Siemens Personal Networks Department, the European Computer-Industry Research Center (ECRC), and the Institute of Communication Networks at the Aachen University of Technology. Popular uses a path-loss model to describe radio-wave transmission and constraint-based programming to optimize the placement of base stations (transmitters) for local wireless communication at company sites.
    [bibtex-key = fru_et_al_planning_cordless_is96]
  248. Jonathan Lever, Mark Wallace, and Barry Richards. Constraint Logic Programming for Scheduling and Planning. BT Technical Journal, 13(1), 1995. [bibtex-key = lever_et_al_clp_sched_plan_bt95]
  249. Thom Frühwirth and Philipp Hanschke. Terminological Reasoning with Constraint Handling Rules. In V. Saraswat and P. Van Hentenryck, editors, Principles and Practice of Constraint Programming, chapter 19. MIT Press, 1995. [bibtex-key = fru_meuss_terminological_reasoning_1995]
  250. Thom Frühwirth. Implementation of Logical Retraction in Constraint Handling Rules with Justifications. In 21st International Conference on Applications of Declarative Programming and Knowledge Management (INAP 2017), 2017. [bibtex-key = fruehwirth2017implementation]
  251. Daniel Gall and Thom Frühwirth. A Decidable Confluence Test for Cognitive Models in ACT-R. In International Joint Conference on Rules and Reasoning (RuleML+RR 2017), July 2017. [bibtex-key = gall2017decidable]
  252. Vincent Nys and Danny De Schreye. Transforming Coroutining Logic Programs into Equivalent CHR Programs. In , April 2017. [bibtex-key = nys2017transforming]
  253. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. A Rule-Based Approach for Automatic Interaction Detection and Annotation. In 21st International Conference Information Visualisation (iV2017), July 2017. [bibtex-key = sharafrule]
  254. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. CHR-Graph: A Platform for Animating Tree and Graph Algorithms. In 21st International Conference Information Visualisation, IV, pages 11-14, July 2017. [bibtex-key = sharaf2017chr]
  255. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. Using Rules to Animate Prolog Programs. In Proceedings of the Doctoral Consortium, Challenge, Industry Track, Tutorials and Posters hosted by International Joint Conference on Rules and Reasoning 2017 (RuleML+RR 2017), 2017. [bibtex-key = sharaf2017using]
  256. Blanchard Allan, Nikolai Kosmatov, and Frédéric Loulergue. A CHR-Based Solver for Weak Memory Behaviors. In 7th Workshop on Constraint Solvers in Testing, Verification, and Analysis (CSTVA), 2016. [bibtex-key = allan2016chr]
  257. Sebastian Krings and Michael Leuschel. Constraint Logic Programming over Infinite Domains with an Application to Proof. In Proc. 30th Workshop on Logic Programming (WLP 2016), 2016. [bibtex-key = krings2016clp]
  258. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. A Rule Based Approach to teach Mathematics using Animation. In Supplementary Proceedings of the RuleML 2016 Challenge, Doctoral Consortium and Industry Track hosted by the 10th International Web Rule Symposium, RuleML 2016, New York, USA, July 6-9, 2016., 2016. [bibtex-key = sharaf2016ruleml]
  259. Nada Sharaf, Slim Abdennadher, and Thom Frühwirth. A Rule-Based Approach for Animating Java Algorithms. In Information Visualisation (IV), 2016 20th International Conference, pages 141-145, 2016. IEEE. [bibtex-key = sharaf2016iv]
  260. Nada Sharaf, Slim Abdennadher, Thom Frühwirth, and Daniel Gall. Animating Cognitive Models and Architectures: A Rule-Based Approach. In Christoph Benzmerb=uller, Geoff Sutcliffe, and Raul Rojas, editors, GCAI 2016. 2nd Global Conference on Artificial Intelligence, volume 41 of EPiC Series in Computing, pages 253-265, 2016. EasyChair. ISSN: 2398-7340. [bibtex-key = sharaf2016animating]
  261. Rafael Caballero, Yolanda Garcìa-Ruiz, and Fernando Sáenz-Pérez. Debugging of wrong and missing answers for datalog programs with constraint handling rules. In Proceedings of the 17th International Symposium on Principles and Practice of Declarative Programming, pages 55-66, 2015. ACM. [bibtex-key = caballero2015debugging]
  262. Verónica Dahl, Sergio Tessaris, and Thom Frühwirth. Imperfect Querying through Womb Grammars plus Ontologies.. In Odile Papini, Salem Benferhat, Laurent Garcia, Marie-Laure Mugnier, Eduardo L. Fermé, Thomas Meyer, Renata Wassermann, Torsten Hahmann, Ken Baclawski, Adila Krisnadhi, Pavel Klinov, Stefano Borgo, Oliver Kutz, and Daniele Porello, editors, JOWO@IJCAI, volume 1517 of CEUR Workshop Proceedings, 2015. CEUR-WS.org. [WWW] Keyword(s): dblp. [bibtex-key = conf/ijcai/DahlTF15]
  263. Thom Frühwirth. A devil's advocate against termination of direct recursion. In Proceedings of the 17th International Symposium on Principles and Practice of Declarative Programming, pages 103-113, 2015. ACM. [bibtex-key = fruhwirth2015devil]
  264. Daniel Gall and Thom Frühwirth. A refined operational semantics for ACT-R: investigating the relations between different ACT-R formalizations. In Proceedings of the 17th International Symposium on Principles and Practice of Declarative Programming, pages 114-124, 2015. ACM. [bibtex-key = gall2015refined]
  265. Daniel Gall and Thom Frühwirth. An adaptable implementation of ACT-R with refraction in Constraint Handling Rules. In Proceedings of the 13th International Conference on Cognitive Modeling, pages 61-66, 2015. [bibtex-key = gall2015adaptable]
  266. Edmund Soon Lee Lam, Iliano Cervesato, and Nabeeha Fatima. Comingle: Distributed Logic Programming for Decentralized Mobile Ensembles. In Coordination Models and Languages - 17th IFIP WG 6.1 International Conference, COORDINATION 2015, Grenoble, France, 2015, pages 51-66, 2015. [bibtex-key = lam2015]
  267. Uwe Lesta, Ina Schaefer, and Tim Winkelmann. Detecting and Explaining Conflicts in Attributed Feature Models. In Joanne M. Atlee and Stefania Gnesi, editors, Proceedings 6th Workshop on Formal Methods and Analysis in SPL Engineering, FMSPLE@ETAPS 2015, London, UK, 11 April 2015., volume 182 of EPTCS, pages 31-43, 2015. [WWW] [doi:10.4204/EPTCS.182.3] [bibtex-key = DBLP:journals/corr/LestaSW15]
  268. Francesco Santini. Argument-based constraint logic-programming in satisfiability modulo CHR. In 12th International Workshop on Argumentation in Multi-Agent Systems. Informal Proceedings, 2015. [PDF] [bibtex-key = santini2015argument]
  269. Maged Shalaby, Slim Abdennadher, Nada Sharaf, and Ghada Fakhry. Learning Instance-Level Constraints in Folksonomies for Semi-supervised Clustering using CHR. In 29nd Workshop on (Constraint) Logic Programming (WLP 2015), pages 79-88, 2015. [PDF] [bibtex-key = shalaby2015learning]
  270. N. Sharaf, S. Abdennadher, and T. Frühwirth. DiagrammaticCHR: A Diagrammatic Representation of CHR Programs. In 2015 19th International Conference on Information Visualisation, pages 121-126, July 2015. ISSN: 1550-6037. [doi:10.1109/iV.2015.31] Keyword(s): constraint handling, program visualisation, visual languages, CHR program diagrammatic representation, DiagrammaticCHR, animation, constraint handling rules, general purpose language, visualization features, Animation, Color, Joining processes, Semantics, Solids, Syntactics, Visualization, Constraint Handling Rules, Program Animation, Visual Language. [bibtex-key = sharaf2015diagrammatic]
  271. Stefano Bistarelli, Gianpiero Costantino, Fabio Martinelli, and Francesco Santini. An Improved Role-Based Access to Android Applications with JCHR. In Proceedings of the 2014 Ninth International Conference on Availability, Reliability and Security, ARES '14, Washington, DC, USA, pages 341-348, 2014. IEEE Computer Society. ISBN: 978-1-4799-4223-7. [WWW] [doi:10.1109/ARES.2014.52] [bibtex-key = Bistarelli:2014:IRA:2703000.2703248]
  272. Emanuele De Angelis, Fabio Fioravanti, Alberto Pettorossi, and Maurizio Proietti. VeriMAP: A Tool for Verifying Programs through Transformations. In Erika Ábrahám and Klaus Havelund, editors, Tools and Algorithms for the Construction and Analysis of Systems - 20th International Conference, TACAS 2014, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2014, Grenoble, France, April 5-13, 2014. Proceedings, volume 8413 of Lecture Notes in Computer Science, pages 568-574, 2014. Springer. ISBN: 978-3-642-54861-1. [WWW] [doi:10.1007/978-3-642-54862-8_47] [bibtex-key = DBLP:conf/tacas/AngelisFPP14]
  273. Rémy Haemmerlé. On Combining Backward and Forward Chaining in Constraint Logic Programming. In Proceedings of the 16th International Symposium on Principles and Practice of Declarative Programming, PPDP '14, New York, NY, USA, pages 213-224, 2014. ACM. ISBN: 978-1-4503-2947-7. [WWW] [doi:10.1145/2643135.2643144] Keyword(s): CHR, CLP, backward & forward chaining, confluence. [bibtex-key = haemmerle2014combining]
  274. Rahul Singhal and Martin Henz. Automated Generation of Region Based Geometric Questions. In 26th IEEE International Conference on Tools with Artificial Intelligence, ICTAI 2014, Limassol, Cyprus, November 10-12, 2014, pages 838-845, 2014. IEEE Computer Society. ISBN: 978-1-4799-6572-4. [WWW] [doi:10.1109/ICTAI.2014.129] [bibtex-key = DBLP:conf/ictai/SinghalH14]
  275. Rahul Singhal, Martin Henz, and Kevin McGee. Automated Generation of High School Geometric Questions Involving Implicit Construction. In Susan Zvacek, Maria Teresa Restivo, James Onohuome Uhomoibhi, and Markus Helfert, editors, CSEDU 2014 - Proceedings of the 6th International Conference on Computer Supported Education, Volume 1, Barcelona, Spain, 1-3 April, 2014, pages 467-472, 2014. SciTePress. ISBN: 978-989-758-020-8. [WWW] [doi:10.5220/0004947904670472] [bibtex-key = DBLP:conf/csedu/SinghalHM14]
  276. Slim Abdennadher, Ghada Fakhry, and Nada Sharaf. Implementation of the Operational Semantics for CHR with User-defined Rule Priorities. In Henning Christiansen and Jon Sneyers, editors, CHR13l, pages 1-12, July 2013. KULCW, Technical report CW 641. [WWW] [PDF] Keyword(s): implementation, priorities, CHR 2013, CHR 2013. [bibtex-key = abdennadher_sts_chr13]
  277. Veronica Dahl, Sinan Egilmez, Joao Martins, and Emilio Miralles. On Failure-Driven Constraint-Based Parsing through CHRG. In Henning Christiansen and Jon Sneyers, editors, CHR13l, pages 13-24, July 2013. KULCW, Technical report CW 641. [WWW] [PDF] Keyword(s): linguistics, CHR 2013, CHR 2013. [bibtex-key = dahl_parsing_chr13]
  278. Gregory James Duck. Satisfiability modulo constraint handling rules. In IJCAI, 2013. [bibtex-key = duck2013satisfiability]
  279. Gregory J. Duck, Joxan Jaffar, and Nicolas C. H. Koh. Constraint-Based Program Reasoning with Heaps and Separation. In Christian Schulte, editor, CP, volume 8124 of Lecture Notes in Computer Science, pages 282-298, 2013. Springer. ISBN: 978-3-642-40626-3. [bibtex-key = DBLP:conf/cp/DuckJK13]
  280. David Fabian and Radek Marìk. Configuration Dynamics Verification Using UPPAAL. In 15 th International Configuration Workshop, pages 35, 2013. [bibtex-key = fabian2013configuration]
  281. Edmund S.L. Lam and Iliano Cervesato. Decentralized Execution of Constraint Handling Rules for Ensembles. In Proceedings of the 15th Symposium on Principles and Practice of Declarative Programming, pages 205-216, 2013. ACM. [bibtex-key = lam2013decentralized]
  282. Amr Osman, Amira Zaki, and Slim Abdennadher. CHR Meets MapReduce. In Henning Christiansen and Jon Sneyers, editors, CHR13l, pages 25-38, July 2013. KULCW, Technical report CW 641. [WWW] [PDF] Keyword(s): applications, CHR 2013, CHR 2013. [bibtex-key = osman_mapreduce_chr13]
  283. Nada Sharaf, Injy Hamed, and Slim Abdennadher. Tagging Reasoning System using CHR. In Henning Christiansen and Jon Sneyers, editors, CHR13l, pages 61-69, July 2013. KULCW, Technical report CW 641. [WWW] [PDF] Keyword(s): applications, CHR 2013, CHR 2013. [bibtex-key = sharaf_tagging_chr13]
  284. Ghada Fakhry Slim Abdennadher and Nada Sharaf. Towards The Implementation of Source-to-Source Transformation Tool for CHR Operational Semantics. In Gopal Gupta, editor, LOPSTR13prel, 2013. [bibtex-key = abd_sts_lopstr13]
  285. Jon Sneyers, Daniel De Schreye, and Thom Frühwirth. CHRiSM and Probabilistic Argumentation Logic. In Henning Christiansen and Jon Sneyers, editors, CHR13l, pages 39-52, July 2013. KULCW, Technical report CW 641. [WWW] [PDF] Keyword(s): CHRiSM, applications, CHR 2013, CHR 2013. [bibtex-key = sneyers_pal_chr13]
  286. Amira Zaki, Matthias Rau, and Thom Frühwirth. CHR-IDE: An Eclipse Plug-In for Constraint Handling Rules. In Henning Christiansen and Jon Sneyers, editors, CHR13l, pages 53-60, July 2013. KULCW, Technical report CW 641. [WWW] [PDF] Keyword(s): debugging, CHR 2013, CHR 2013. [bibtex-key = zaki_ide_chr13]
  287. Slim Abdennadher and Nada Sharaf. Visualization of CHR through Source-to-Source Transformation. In Agostino Dovier and Vìtor Santos Costa, editors, Technical Communications of the 28th International Conference on Logic Programming (ICLP'12), volume 17 of Leibniz International Proceedings in Informatics (LIPIcs), Dagstuhl, Germany, pages 109-118, 2012. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik. ISBN: 978-3-939897-43-9. ISSN: 1868-8969. [WWW] [doi:http://dx.doi.org/10.4230/LIPIcs.ICLP.2012.109]
    Annotation:
    Keywords: Source-to-Source Transformation, Constraint Handling Rules, Visualization
    [bibtex-key = abdennadher_et_al:LIPIcs:2012:3614]
  288. Alia El Bolock, Amira Zaki, and Thom Frühwirth. Substitution-based CHR Solver for Bivariate Binomial Equation Sets. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 41-50, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): applications, algorithms, CHR 2012, CHR 2012.
    Abstract:
    Various methods for solving non-linear algebraic systems exist, as this question is amongst the most popular in both the realm of mathematics and computation. As most of these methods use approximations, this work focuses on finding and directly solving a tractable subset. Bivariate binomial systems of non-linear polynomial equations were chosen and solved through simulating the by hand method, using the declarative logic programming language Constraint Handling Rules. Substitution methods and different equation notations are used to extend the solvability of the subset.
    [bibtex-key = bolock_equations_chr12]
  289. Fabian Buettner and Jordi Cabot. Lightweight String Reasoning for OCL. In 8th European Conference on Modelling Foundations and Applications (ECMFA), 2012. [bibtex-key = buettner_string_reasoning_ecmfa12]
  290. Ruoyu Chen, Lejian Liao, and Zhi Fang. Contracting of Web Services with Constraint Handling Rules. In SERVICES, pages 211-218, 2012. IEEE. ISBN: 978-1-4673-3053-4. [doi:10.1109/SERVICES.2012.36] [bibtex-key = DBLP:conf/services/ChenLF12]
  291. Henning Christiansen. An adaptation of Constraint Handling Rules for Interactive and Intelligent Installations. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 1-15, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): applications, CHR 2012, CHR 2012.
    Abstract:
    Constraint Handling Rules, CHR, have proved to be effective for a large range of reasoning task, which is also interesting in different sorts of interactive installations. Typically, such an installation involves a large number of cooperating software components that need to refer to a common knowledge. Using CHR's constraint stores for knowledge representation may be appealing from a theoretical point of view, but suffers from the inherent limitation of CHR, that a constraint store disappears immediately after a query has been evaluated. An extension to CHR is proposed, which allows different processes to reason over and maintain a common knowledge base represented as text files containing constraints. Constraints are automatically read from and written to the files before and after a query has been executed, which means that the intended style of programming deviates only very little from traditional CHR programming.
    [bibtex-key = christiansen_iichr_chr12]
  292. János Csorba, Zsolt Zombori, and Péter Szeredi. Pros and Cons of Using CHR for Type Inference. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 16-31, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): type systems, CHR 2012, CHR 2012.
    Abstract:
    We report on using logic programming and in particular the Constraint Handling Rules extension of Prolog to provide static type analysis for the Q functional language. We discuss some of the merits and difficulties of CHR that we came across during implementation of a type inference tool.
    [bibtex-key = csorba_chr_for_type_inference_chr12]
  293. Veronica Dahl, Bradley Coleman, J. Emilio Miralles, and Erez Maharshak. CHR for Social Responsibility. In Agostino Dovier and Vìtor Santos Costa, editors, Technical Communications of the 28th International Conference on Logic Programming (ICLP'12), volume 17 of Leibniz International Proceedings in Informatics (LIPIcs), Dagstuhl, Germany, pages 370-380, 2012. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik. ISBN: 978-3-939897-43-9. ISSN: 1868-8969. [WWW] [doi:http://dx.doi.org/10.4230/LIPIcs.ICLP.2012.370]
    Annotation:
    Keywords: Constraint handling rules, principled decision making, informed voting, client directed voting, social responsibility.
    [bibtex-key = dahl_et_al:LIPIcs:2012:3637]
  294. Veronica Dahl and Juan Emilio Miralles. Womb Grammars: Constraint Solving for Grammar Induction. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 32-40, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): linguistics, CHR 2012, CHR 2012.
    Abstract:
    We present Womb Grammars, a novel constraint-based framework implemented in CHRG and particularly useful for inducing, from known linguistic constraints that describe phrases in a language called the source, the linguistic constraints that describe phrases in another language, called the target. We present as well an application that uses as source an existing language fairly related to the target. Next we propose and motivate an intriguing research thread that uses as source language a (non-natural but coupled with our framework, generatively very powerful) universal language of our own device. Finally, we discuss further ramifications of our work.
    [bibtex-key = dahl_womb_grammars_chr12]
  295. Veronica Dahl, Emilio Miralles, and Leonor Becerra-Bonache. On Language Acquisition through Womb Grammars. In Proceedings of the 7th International Workshop on Constraint Solving and Language Processing, France, pages 99-105, 2012. [WWW] [PDF]
    Abstract:
    We propose to automate the field of language acquisition evaluation through Constraint Solving; in particular through the use of Womb Grammars. Womb Grammar Parsing is a novel constraint based paradigm that was devised mainly to induce grammatical structure from the description of its syntactic constraints in a related language. In this paper we argue that it is also ideal for automating the evaluation of language acquisition, and present as proof of concept a CHRG system for detecting which of fourteen levels of morphological proficiency a child is at, from a representative sample of the child's expressions. Our results also uncover ways in which the linguistic constraints that characterize a grammar need to be tailored to language acquisition applications. We also put forward a proposal for discovering in what order such levels are typically acquired in other languages than English. Our findings have great potential practical value, in that they can help educators tailor the games, stories, songs, etc. that can aid a child (or a second language learner) to progress in timely fashion into the next level of proficiency, and can as well help shed light on the processes by which languages less studied than English are acquired.
    [bibtex-key = dahl:hal-00751850]
  296. Rémy Haemmerlé. Coinductive Proof over Streams as CHR Confluence Proofs. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 51-65, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): confluence, CHR 2012, CHR 2012.
    Abstract:
    Coinduction is an important theoretical tool for defining and reasoning about unbound data structures (such as streams, graphs, infinite trees, rational numbers ...), and infinite-behavior systems. Confluence is a fundamental property of {C}onstraint {H}andling {R}ules ({CHR}) since, as in other rewriting formalisms, it guarantees that the computations are not dependent on rule application order, and also because it implies the logical consistency of the program declarative view. In this paper, we illustrate how the confluence of CHR can be used to prove universal coinductive properties. In particular, we give several examples of bisimulation proofs over streams.
    [bibtex-key = haemmerle_coinductive_proofs_chr12]
  297. Ester Martìnez-Martin, M. Teresa Escrig, and Angel P. Del Pobil. Qualitative Velocity Model: Representation, Reasoning and Application. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 66-81, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): applications, CHR 2012, CHR 2012.
    Abstract:
    On the way to autonomous systems, one of the key issues concerns spatial reasoning for solving problems dealing with uncertainty. From the starting point of human nature, information must be represented in a way that any system can reason with imprecise knowledge about different physical aspects and make correct decisions from them. Keeping this idea in mind, this paper presents the qualitative model of velocity including representation, reasoning process and a real robotic application.
    [bibtex-key = martinez_qualitative_velocity_chr12]
  298. Colin Nicholson and Danny De Schreye. Relevancy analysis as a basis for improved tabling in CHRiSM. In Elvira Albert, editor, Proceedings of the 22nd International Symposium on Logic-Based Program Synthesis and Transformation,, pages 100-114, September 2012. [WWW] [bibtex-key = 369440]
  299. M. Spies. Continous Monitoring for IT Governance with Domain Ontologies. In Database and Expert Systems Applications (DEXA), 2012 23rd International Workshop on, pages 43-47, Sept 2012. ISSN: 1529-4188. [doi:10.1109/DEXA.2012.36] Keyword(s): Description Logic.
    Abstract:
    We present the practical context, design rationale and application basics of a domain ontology capturing industry standards for defining, controlling and auditing IT Governance.
    [bibtex-key = 6327401]
  300. Andrea Triossi, Salvatore Orlando, Alessandra Raffaetà, and Thom Frühwirth. Compiling CHR to parallel hardware. In Proceedings of the 14th symposium on Principles and Practice of declarative programming, pages 173-184, 2012. ACM. [bibtex-key = triossi2012compiling]
  301. Amira Zaki, Thom Frühwirth, and Ilvar Geller. Parallel Execution of Constraint Handling Rules on a Graphical Processing Unit. In Jon Sneyers and Thom Frühwirth, editors, CHR12l, pages 82-90, September 2012. KULCW, Technical report CW 624. [WWW] [PDF] Keyword(s): parallelism, implementation, CHR 2012, CHR 2012.
    Abstract:
    Graphical Processing Units (GPUs) consist of hundreds of small cores, collectively operating to provide massive computation capabilities. The aim of this work is to utilize this technology to execute Constraint Handling Rules (CHR) which are inherently parallel. A translation scheme is defined to transform a subset of CHR to C++, then to use a GPU to fire the rules on all combinations of constraints. As proof of concept, the scheme was performed on several CHR examples.
    [bibtex-key = zaki_parallel_gpu_chr12]
  302. Viktor de Boer, Jan Wielemaker, Judith van Gent, Michiel Hildebrand, Antoine Isaac, Jacco van Ossenbruggen, and Guus Schreiber. Supporting Linked Data Production for Cultural Heritage Institutes: The Amsterdam Museum Case Study. In Elena Simperl, Philipp Cimiano, Axel Polleres, Óscar Corcho, and Valentina Presutti, editors, ESWC, volume 7295 of Lecture Notes in Computer Science, pages 733-747, 2012. Springer. ISBN: 978-3-642-30283-1. [bibtex-key = DBLP:conf/esws/BoerWGHIOS12]
  303. Victor de Boer, Jan Wielemaker, Judith van Gent, Michiel Hildebrand, Antoine Isaac, Jacco van Ossenbruggen, and Guus Schreiber. Supporting Linked Data Production for Cultural Heritage institutes: The Amsterdam Museum Case Study. In 9th Extended Semantic Web Conference (ESWC 2012), May 2012. [bibtex-key = deboer_amsterdam_museum_eswc12]
  304. Marco Alberti, Marco Gavanelli, and Evelina Lamma. The CHR-based Implementation of the SCIFF Abductive System. In Proc. 26th CILC: 26-esimo Convegno Italiano di Logica Computazionale, August-September 2011. [bibtex-key = alberti_sciff_chr_cilc11]
  305. J. Cheney. Satisfiability algorithms for conjunctive queries over trees. In Proceedings of the 14th International Conference on Database Theory, pages 150-161, 2011. ACM. [bibtex-key = cheney2011satisfiability]
  306. Henning Christiansen and Amr Hany Saleh. Modeling Dependent Events with CHRiSM for Probabilistic Abduction. In Jon Sneyers, editor, CHR11l, pages 48-63, September 2011. GUC, Technical report. [PDF] Keyword(s): abduction, probabilistic CHR, CHRiSM, CHR 2011, CHR 2011.
    Abstract:
    Most earlier approaches to probabilistic abductive logic programming are based on the assumption that abducibles represent independent events. This enables eient and incremental calculation of probabilities, but may not be suitable for all real world problems. As an attempt to introduce such dependencies in a logic programming setting, we have applied CHRiSM, which is a recent probabilistic extension to Constraint Handling Rules, for specication and evaluation of probability distributions over dependent abducibles. It is shown that this principle integrates well with earlier work on probabilistic abduction based on CHR, generalizing it to handle such dependencies. We present our rst experiments with a working implementation that show the potential for interesting applications. On the other hand, our experience underlines problems concerning high complexity due to lacking incremental methods for probability calculation.
    [bibtex-key = christiansen_saleh_dependent_events_chr11]
  307. Verónica Dahl. CHR for Spoken and other Biological Languages. In Jon Sneyers, editor, CHR11l, pages 4-18, September 2011. GUC, Technical report. Note: Invited talk. [PDF] Keyword(s): abduction, linguistics, applications, CHR 2011, CHR 2011.
    Abstract:
    CHR is now well established as an invaluable tool for computing and other formal science applications. Much less studied is their use in the humanistic sciences. In this article we bring together our personal view on applying Constraint Reasoning as embodied in CHR to joining the humanistic with the formal sciences, through the link of language understood in a broad sense as including both spoken languages and molecular biology languages. and we try to distill from these heterogeneous enterprises some common threads that can possibly lead to an embryonic model of humanistic investigation through CHR. The applications we cover include such themes as a dual processing scheme for both human and biological languages; decoding nucleic acid strings through human language; DNA replication as a model for computational linguistics; multi-disciplinary biological knowledge representation for early cancer diagnosis; RNA-inspired analysis of poetry; parsing medical text into de-identied databases; and biological concept-formation.
    [bibtex-key = dahl_languages_chr11]
  308. Marcel Dausend and Frank Raiser. Model Transformation using Constraint Handling Rules as a basis for Model Interpretation. In Jon Sneyers, editor, CHR11l, pages 64-78, September 2011. GUC, Technical report. [PDF] Keyword(s): applications, CHR 2011, CHR 2011.
    Abstract:
    In this paper, we present a model transformation approach aiming to simplify automatic processing of UML state machine models, especially for interpretation. The main requirements are easing the implementation of the interpreter and reducing the number of calculations necessary to execute a model. Our model transformation preserves the semantics and is implemented using CHR. The result of the transformation is an UML state machine model based on the concept of compound transitions. Furthermore we provide an interpreter for those models which supports a comprehensive subset of UML state machine concepts, i. a. junction, fork, join. Our preliminary results show that state machine interpreters can prot from the former model transformation. It simplies certain aspects of the interpreter implementation and positively aects the performance of the interpreter, e.g. regarding transition selection and transition execution.
    [bibtex-key = dausend_raiser_model_transformation_chr11]
  309. Krishna S. R. Dubba, Mehul Bhatt, Frank Dylla, David C. Hogg, and Anthony G. Cohn. Interleaved Inductive-Abductive Reasoning for Learning Complex Event Models. In Stephen Muggleton, Alireza Tamaddoni-Nezhad, and Francesca A. Lisi, editors, ILP, volume 7207 of Lecture Notes in Computer Science, pages 113-129, 2011. Springer. ISBN: 978-3-642-31950-1. [bibtex-key = DBLP:conf/ilp/DubbaBDHC12]
  310. Armando Gonçalves, Marcos Aurélio Almeida da Silva, Pierre Deransart, and Jacques Robin. Towards a Generic Trace for Rule Based Constraint Reasoning. In Jon Sneyers, editor, CHR11l, pages 32-47, September 2011. GUC, Technical report. [PDF] Keyword(s): debugging, CHR 2011, CHR 2011.
    Abstract:
    CHR is a very versatile programming language that allows programmers to declaratively specify constraint solvers. An important part of the development of such solvers is in their testing and debugging phases. Current CHR implementations support those phases by offering tracing facilities with limited information. In this paper, we propose a new trace for CHR which contains enough information to analyze any aspects of CHR$^\vee$ execution at some general abstract level. This approach is based on the idea of generic trace. Such a trace is formally defined as an extension of the refined CHR$^\vee$ semantics. It is currently prototyped in a SWI Prolog based CHR implementation.
    [bibtex-key = goncalves_generic_trace_chr11]
  311. R. Haemmerlé, P. Lopez-Garcia, and M.V. Hermenegildo. CLP Projection for Constraint Handling Rules. In Michael Hanus, editor, PPDP11l, pages 137-148, July 2011. ACM. [doi:10.1145/2003476.2003496] Keyword(s): semantics, related formalisms, termination, confluence.
    Abstract:
    This paper introduces and studies the notion of CLP projection for Constraint Handling Rules (CHR). The CLP projection consists of a naive translation of CHR programs into Constraint Logic Programs (CLP). We show that the CLP projection provides a safe operational and declarative approximation for CHR programs. We demonstrate moreover that a confluent CHR program has a least model, which is precisely equal to the least model of its CLP projection (closing hence a ten year-old conjecture by Abdennadher et al.). Finally, we illustrate how the notion of CLP projection can be used in practice to apply CLP analyzers to CHR. In particular, we show results from applying AProVE to prove termination, and CiaoPP to infer both complexity upper bounds and types for CHR programs.
    [bibtex-key = haemmerle2011clp]
  312. Christian Theil Have. Constraints and Global Optimization for Gene Prediction Overlap Resolution. In Alessandro Dal Palù, Agostino Dovier, and Andrea Formisano, editors, WCB'11: Workshop on Constraint Based Methods for Bioinformatics, pages 17-26, September 2011. Keyword(s): applications. [bibtex-key = have_wcb11]
  313. Johannes Langbein, Roland Stelzer, and Thom Frühwirth. A Rule-Based Approach to Long-Term Routing for Autonomous Sailboats. In Robotic Sailing 2011, Part V, pages 195-204, 2011. [doi:10.1007/978-3-642-22836-0_14] Keyword(s): applications. [bibtex-key = langbein_routing_robsail11]
  314. Ester Mart'inez-Martìn and M. Teresa Escrig. A General Qualitative Spatio-Temporal Model Based on Intervals. In QR2011: 25th International Workshop on Qualitative Reasoning, 2011. [bibtex-key = martinez_qr11]
  315. Thierry Martinez. Angelic CHR. In Jon Sneyers, editor, CHR11l, pages 19-31, September 2011. GUC, Technical report. [PDF] Keyword(s): semantics, CHR 2011, CHR 2011.
    Abstract:
    Implementations of CHR follow a committed-choice forwardchaining execution model: the non-determinism of the abstract semantics is partly rened with extra-logical syntactic convention on the program order and possibly notations for weighted semantics (with priorities or probabilities), and partly left unspecied in the underlying compiler. This paper proposes an alternative execution model which explores all the possible choices, by opposition to the committed-choice strategy. This execution model is angelic in the sense that if there exists a successful execution strategy (with respect to a given observable), then this strategy will be found. Formally, the set of computed goals is complete with respect to the set of the logical consequences of the interpretation of the initial goal in linear logic. In practice, this paper introduces a new data representation for sets of goals, the derivation nets. Sharing strategies between computation paths can be dened for derivation nets to make execution algorithmically tracktable in some cases where a naive exploration would be exponential. Control for rened execution is recovered with the introduction of user constraints to encode sequencing, fully captured in the linear-logic interpretation. As a consequence of angelic execution, CHR rules become decomposable while preserving accessibility properties. This decomposability makes natural the denition in angelic CHR of meta-interpreters to change the execution strategy. More generally, arbitrary computation can be interleaved during head matching, for custom user constraint indexation and deep guard denition.
    [bibtex-key = martinez_angelic_chr11]
  316. Jose F. Morales, Manuel Hermenegildo, and Rémy Haemmerlé. Modular Extensions for Modular (Logic) Languages. In German Vidal, editor, LOPSTR11l, LNCS, 2011. Keyword(s): extensions. [bibtex-key = morales_lopstr11]
  317. Paolo Pilozzi and Danny De Schreye. Improved termination analysis of CHR using self-sustainability analysis. In German Vidal, editor, LOPSTR11l, LNCS, 2011. Keyword(s): termination. [bibtex-key = pilozzi_improved_termination_lopstr11]
  318. Evgeny Skvortsov, Nima Kaviani, and Veronica Dahl. Chemical Signaling as a Useful Metafor for Resource Management. In Proc. IWANN 2011 (International Work Conference on Artificial Neural Networks), 2011. [bibtex-key = skvortsov_chemical_iwann11]
  319. Evgeny Skvortsov, Nima Kaviani, and Veronica Dahl. Chemical signaling as a useful metaphor for resource management. In Proceedings of the 11th international conference on Artificial neural networks conference on Advances in computational intelligence - Volume Part I, IWANN'11, Berlin, Heidelberg, pages 449-456, 2011. Springer-Verlag. ISBN: 978-3-642-21500-1. [WWW] [bibtex-key = Skvortsov:2011:CSU:2023252.2023316]
  320. Jon Sneyers and Danny De Schreye. Probabilistic Termination of CHRiSM Programs. In German Vidal, editor, LOPSTR11prel, 2011. Keyword(s): termination, CHRiSM, probabilistic CHR. [bibtex-key = sneyers_probabilistic_termination_lopstr11]
  321. Andrea Triossi. Boosting CHR through Hardware Acceleration. In Jon Sneyers, editor, CHR11l, pages 1-3, September 2011. GUC, Technical report. Note: Invited talk. [PDF] Keyword(s): implementation, parallelism, CHR 2011, CHR 2011.
    Abstract:
    The aim of this talk is to present a general framework for compiling Constraint Handling Rules (CHR) to a low level hardware description language (HDL). The benet introduced by a CHR based hardware synthesis is twofold: it increases the abstraction level of the common synthesis workflow and it can give signicant speed up to the execution of a CHR program. I will describe a practical method that set CHR as starting point for a hardware description and afterwards I will show how to integrate the generated hardware code, deployed in a Field Programmable Gate Array (FPGA), within the traditional software execution model of CHR. The result is a prototype CHR execution engine composed of a general purpose processor coupled with a specialized hardware accelerator. The former executes a CHR specication while the latter unburdens the processor by executing in parallel the most computational intensive rules. The talk will have a practical focus, illustrating the achieved performance obtained by a prototype system architecture.
    [bibtex-key = triossi_hardware_acceleration_chr11]
  322. Zsolt Zombori, János Csorba, and Péter Szeredi. Static Type Checking for the Q Functional Language in Prolog. In John Gallagher and Michael Gelfond, editors, Technical Communications of the 27th Intl. Conf. on Logic Programming, volume 11 of Leibniz Intl. Proc. in Informatics (LIPIcs), Dagstuhl, Germany, pages 62-72, July 2011. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik. Keyword(s): type systems. [bibtex-key = zombori_iclp11]
  323. Slim Abdennadher, Haythem Ismail, and Frederick Khoury. Transforming Imperative Algorithms to Constraint Handling Rules. In A. Wolf and U. Geske, editors, WLP '09: Proc. 23rd Workshop on (Constraint) Logic Programming, 2010. Universität Potsdam. [WWW] [bibtex-key = abd_et_al_imperative_to_chr_wlp09]
  324. Marco Alberti, Marco Gavanelli, and Evelina Lamma. Runtime Addition of Integrity Constraints in an Abductive Proof Procedure. In Manuel Hermenegildo and Torsten Schaub, editors, Technical Communications of the 26th Intl. Conf. on Logic Programming, volume 7 of Leibniz Intl. Proc. in Informatics (LIPIcs), Dagstuhl, Germany, July 2010. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik. [doi:10.4230/LIPIcs.ICLP.2010.4] Keyword(s): abduction. [bibtex-key = alberti_gav_lamma_iclp10]
  325. Hariolf Betz, Frank Raiser, and Thom Frühwirth. Persistent Constraints in Constraint Handling Rules. In A. Wolf and U. Geske, editors, WLP '09: Proc. 23rd Workshop on (Constraint) Logic Programming, 2010. Universität Potsdam. [WWW] Keyword(s): parallelism, semantics. [bibtex-key = betz_raiser_fru_persistent_constraints_wlp09]
  326. Stefano Bistarelli, Fabio Martinelli, and Francesco Santini. A formal framework for trust policy negotiation in autonomic systems: abduction with soft constraints. In Proceedings of the 7th international conference on Autonomic and trusted computing, ATC'10, Berlin, Heidelberg, pages 268-282, 2010. Springer-Verlag. ISBN: 3-642-16575-3, 978-3-642-16575-7. [WWW] Keyword(s): abduction. [bibtex-key = Bistarelli:2010:FFT:1927943.1927968]
  327. Henning Christiansen, Christian Theil Have, Ole Torp Lassen, and Matthieu Petit. The Viterbi Algorithm expressed in Constraint Handling Rules. In P. Van Weert and L. De Koninck, editors, CHR10l, July 2010. KULCW, Technical report CW 588. [WWW] [PDF] Keyword(s): CHR 2010, applications, CHR 2010, CHR 2010.
    Abstract:
    The Viterbi algorithm is a classical example of a dynamic programming algorithm, in which pruning reduces the search space drastically, so that a potentially exponential time complexity is reduced to linearity. The central steps of the algorithm, expansion and pruning, can be expressed in a concise and clear way in CHR, but additional control needs to be added in order to obtain the desired time complexity. It is shown how auxiliary constraints, called trigger constraints, can be applied to fine-tune the order of CHR rule applications in order to reach this goal. It is indicated how properties such as confluence can be useful for showing such optimized programs correct.
    [bibtex-key = christiansen_et_al_viterbi_chr10]
  328. Verónica Dahl, M. Dolores Jiménez-López, and Olivier Perriquet. Poetic RNA: Adapting RNA Design Methods to the Analysis of Poetry. In Proc. 8th Intl. Conf. Practical Applications of Agents and Multiagent Systems, volume 71 of Advances in Soft Computing, pages 403-410, April 2010. SV. [doi:10.1007/978-3-642-12433-4_48] Keyword(s): applications, linguistics.
    Abstract:
    The style in which a Ribonucleic Acid (RNA) molecule folds in space obeys laws of nucleotide binding and attraction which are encoded in its primary structure, that is, in the sequence of nucleotides conforming it. Natural language sentences can also be viewed as encodings for a structure in space -a parse tree- which exhibits relationships or bindings between its parts. We explore the possibilities in adapting a recent and simple methodology for bioinformatics -which has been successfully used for RNA design- to the problem of parsing poems that follow specific stylistic trends. The methodology introduced in this paper can be expressed in terms of a multi-agent system that includes two types of agents: linguistic agents and probabilistic agents.
    [bibtex-key = dahl_et_al_poetic_rna_paams10]
  329. Andreas Falkner, Alois Haselböck, and Gottfried Schenner. Modeling Technical Product Configuration Problems. In Lothar Hotz and Alois Haselböck, editors, Workshop on Configuration at 19th European Conference on Artificial Intelligence ECAI 2010, August 2010. [bibtex-key = falkner_configuration_10]
  330. Florian Geiselhart, Frank Raiser, Jon Sneyers, and Thom Frühwirth. MTSeq -- Multi-touch-enabled music generation and manipulation based on CHR. In P. Van Weert and L. De Koninck, editors, CHR10l, July 2010. KULCW, Technical report CW 588. [WWW] [PDF] Keyword(s): CHR 2010, CHRiSM, applications, CHR 2010, CHR 2010.
    Abstract:
    We present MTSeq, an application that combines GUI-driven multi-touch input technology with the CHR-based music generation system APOPCALEAPS and an advanced audio engine. This combination leads to an extended user experience and an intuitive, playful access to the CHR music generation system, and thus introduces CHR to musicians and other non-computer-scientists in an appropriate way. The application is fully modularized and its parts are loosely interconnected through a standard IP networking layer, so it is optionally distributable across multiple machines.
    [bibtex-key = geiselhart_et_al_mtseq_chr10]
  331. Ralf Gerlich. Generic and Extensible Automatic Test Data Generation for Safety Critical Software with CHR. In P. Van Weert and L. De Koninck, editors, CHR10l, July 2010. KULCW, Technical report CW 588. [WWW] [PDF] Keyword(s): CHR 2010, applications, testing, CHR 2010, CHR 2010.
    Abstract:
    We present a new method for automatic test data generation (ATDG) applying to semantically annotated controlow graphs (CFGs), covering both ATDG based on source code and assembly or virtual machine code. The method supports a generic set of test coverage criteria, including all structural coverage criteria currently in use in industrial software test for safety critical software. Several known and new strategies are supported for avoiding infeasible paths, that is paths in the CFG for which no input exists leading to their execution. We describe the implementation of the method in CHR$^\vee$ and discuss divculties and advantages of CHR in this context.
    [bibtex-key = gerlich_atdg_chr10]
  332. Johannes Langbein, Frank Raiser, and Thom Frühwirth. A State Equivalence and Confluence Checker for CHR. In P. Van Weert and L. De Koninck, editors, CHR10l, July 2010. KULCW, Technical report CW 588. [WWW] [PDF] Keyword(s): confluence, semantics, CHR 2010, CHR 2010, CHR 2010.
    Abstract:
    Analyzing confluence of CHR programs manually can be an impractical and time consuming task. Based on a new theorem for state equivalence, this work presents the first tool for testing equivalence of CHR states. As state equivalence is an essential component of confluence analysis, we apply this tool in the development of a confluence checker that overcomes limitations of existing checkers. We further provide evaluation results for both tools and detail their modular design, which allows for extensions and reuse in future implementations of CHR tools.
    [bibtex-key = langbein_et_al_confluence_checker_chr10]
  333. Yisong Liu, Zhihua Yin, Huijuan Zhu, and Lili Wang. Handling Negative Disjunction Constraints (or_not_holds) in FLUX. In ICCAE 2010: 2nd Intl. Conf. Computer and Automation Engineering, pages 514-518, February 2010. IEEE. [doi:10.1109/ICCAE.2010.5451264] Keyword(s): FLUX, applications.
    Abstract:
    FLUX is a constraint logic programming language based on Fluent Calculus, using which agents can reason logically from their actions and sensor information in incomplete states. The incomplete state is encoded by the constraints in Constraint Handling Rules (CHRs). However, the existing constrains in FLUX are not complete to cover all Fluent Calculus state formulas, which to some extent restricts the range of applications of FLUX. We address this problem by adding negative disjunction constraints into FLUX, which enhances the ability of FLUX to express incomplete states, and the correctness is proved using the semantics of the Fluent Calculus.
    [bibtex-key = liu_yin_zhu_wang_negative_disj_iccae10]
  334. Ahmed Magdy, Frank Raiser, and Thom Frühwirth. Implementing Dynamic Programming Recurrences in Constraint Handling Rules with Rule Priorities. In Slim Abdennadher, editor, WLP10l, September 2010. [WWW] Keyword(s): priorities. [bibtex-key = magdy_raiser_fru_dynamic_progr_recurr_wlp10]
  335. Thierry Martinez. Semantics-preserving translations between Linear Concurrent Constraint Programming and Constraint Handling Rules. In M. Fernández, editor, PPDP10l, pages 57-66, July 2010. ACM. [doi:10.1145/1836089.1836097] Keyword(s): semantics, related formalisms, linear logic.
    Abstract:
    The Constraint Simplification Rules (CSR) subset of CHR and the flat subset of LCC, where agent nesting is restricted, are very close syntactically and semantically. The first contribution of this paper is to provide translations between CSR and flat-LCC. The second contribution is a transformation from the full LCC language to flat-LCC which preserves semantics. This transformation is similar to λ-lifting in functional languages. In conjunction with the equivalence between CHR and CSR with respect to the original operational semantics, these results lead to semantics-preserving translations from full LCC to CHR and conversely. Immediate consequences of this work include new proofs for CHR linear logic and phase semantics, relying on corresponding results for LCC, plus an encoding of the λ-calculus in CHR.
    [bibtex-key = martinez_lccp_chr_ppdp10]
  336. Paolo Pilozzi and Danny De Schreye. Scaling termination proofs by a characterization of cycles in CHR. In Peter Schneider-Kamp, editor, 11th International Workshop on Termination, Edinburgh, United Kingdom, July 2010. Keyword(s): termination. [bibtex-key = pilozzi_scaling_termination_wst11]
  337. Paolo Pilozzi, Tom Schrijvers, and Maurice Bruynooghe. A transformational approach for proving properties of the CHR constraint store. In Danny De Schreye, editor, LOPSTR09l, volume 6037 of LNCS, pages 22-36, 2010. SV. [doi:10.1007/978-3-642-12592-8_3] Keyword(s): termination.
    Abstract:
    Proving termination of, or generating efficient control for Constraint Handling Rules (CHR) programs requires information about the kinds of constraints that can show up in the CHR constraint store. In contrast to Logic Programming (LP), there are not many tools available for deriving such information for CHR. Hence, instead of building analyses for CHR from scratch, we define a transformation from CHR to Prolog and reuse existing analysis tools for Prolog. The proposed transformation has been implemented and combined with PolyTypes 1.3, a type analyser for Prolog, resulting in an accurate description of the types of CHR programs. Moreover, the transformation is not limited to type analysis. It can also be used to prove other properties of the constraints showing up in constraint stores, using tools for Prolog.
    [bibtex-key = pilozzi_schr_bruyn_store_properties_lopstr09]
  338. H. Plociniczak and S. Eisenbach. JErlang: Erlang with Joins. In Coordination Models and Languages, pages 61-75, 2010. Springer. [bibtex-key = plociniczak2010jerlang]
  339. Frank Raiser and Thom Frühwirth. Exhaustive Parallel Rewriting with Multiple Removals. In Slim Abdennadher, editor, WLP10l, September 2010. [WWW] Keyword(s): parallelism. [bibtex-key = raiser_fru_parallel_wlp10]
  340. Jon Sneyers. Result-directed CHR Execution. In P. Van Weert and L. De Koninck, editors, CHR10l, July 2010. KULCW, Technical report CW 588. [WWW] [PDF] Keyword(s): CHR 2010, CHRiSM, probabilistic CHR, CHR 2010, CHR 2010.
    Abstract:
    The traditional execution mode of CHR is bottom-up, that is, given a goal, the result is computed by exhaustively applying rules. This paper proposes a result-directed execution mode for CHR, to be used when both the goal and the result are known, and the task is to find all corresponding derivations. Result-directed execution is needed in the context of CHRiSM, a probabilistic extension of CHR in which goals typically have a large number of possible results. The performance of result-directed execution is greatly improved by adding early-fail rules.
    [bibtex-key = sneyers_result_directed_chr10]
  341. Jon Sneyers and Danny De Schreye. APOPCALEAPS: Automatic Music Generation with CHRiSM. In G. Danoy and others, editors, 22nd Benelux Conference on Artificial Intelligence (BNAIC 2010), Luxembourg, October 2010. Keyword(s): CHRiSM, applications.
    Abstract:
    We present a new system for automatic music generation, in which music is modeled using very high level probabilistic rules. The probabilistic parameters can (at least in principle) be learned automatically from examples, resulting in a system for personalized music generation.
    [bibtex-key = apopcaleaps]
  342. Andrea Triossi, Salvatore Orlando, Alessandra Raffaeta, Frank Raiser, and Thom Frühwirth. Constraint-Based Hardware Synthesis. In Slim Abdennadher, editor, WLP10l, September 2010. [WWW] Keyword(s): applications. [bibtex-key = triossi_et_al_hardware_wlp10]
  343. Peter Van Weert. Join Ordering for Constraint Handling Rules: Putting Theory into Practice. In P. Van Weert and L. De Koninck, editors, CHR10l, July 2010. KULCW, Technical report CW 588. [WWW] [PDF] Keyword(s): CHR 2010, implementation, optimizing compilation, CHR 2010, CHR 2010.
    Abstract:
    Join ordering is the NP-complete problem of finding the optimal order in which the different conjuncts of multi-headed rules are joined. Join orders are the single most important determinants for the runtime complexity of CHR programs. Nevertheless, all current systems use ad-hoc join ordering heuristics, often using greedy, very error-prone algorithms. As a first step, Leslie De Koninck and Jon Sneyers therefore worked out a more realistic, flexible formal cost model. In this work-in-progress paper, we show how we created a first practical implementation of static join ordering based on their theoretical model.
    [bibtex-key = vanweert_join_chr10]
  344. Marcos Aurélio de Almeida Silva and Jacques Robin. Extending CHR with objects under a variety of inheritance and world-closure assumptions. In F. Raiser and J. Sneyers, editors, CHR09l, pages 3-17, July 2009. KULCW, Technical report CW 555. [PDF] Keyword(s): CHR 2009, extensions, CHR 2009, CHR 2009.
    Abstract:
    In this paper, we present CHORD (Constraint Handling Object-oriented Rules with Disjunction) an Object-Oriented (OO) extension of CHRD. Syntactically, CHORD integrates two versatile dual programming and knowledge representation languages: Flora, a hybrid OO rule-based language and CHRD. A CHORD program extends CHRD by allowing Flora-style object constraints (o-constraints) in the head, guard or body of its rules. Orthogonal to its rules, a CHORD program also contains semantic assumption directives, an innovative construct that maximizes semantic versatility. Each directive defines a point along one dimension of the space of semantic assumptions made by various OO and rule-based languages in order to complete the knowledge explicitly specified in them by complementary knowledge left implicit by the programmer. Among others, these assumptions specify what kind of world closure and inheritance is desired.
    [bibtex-key = aurelio_robin_objects_chr09]
  345. Verónica Dahl, Baohua Gu, and Erez Maharshak. A Hyprolog Parsing Methodology for Property Grammars. In IWANN '09: Proc. 10th Intl. Workshop on Artif. Neural Networks, volume 5517 of LNCS, pages 480-487, 2009. SV. [doi:10.1007/978-3-642-02478-8_60] Keyword(s): linguistics.
    Abstract:
    Property Grammars, or PGs, belong to a new family of linguistic formalisms which view a grammar as a set of linguistic constraints, and parsing as a constraint satisfaction problem. Rigid hierarchical parsing gives way to flexible mechanisms which can handle incomplete, ambiguous or erroneous text, and are thus more adequate for new applications such as speech recognition, internet mining, controlled languages and biomedical information. The present work contributes a) a new parsing methodology for PGs in terms of Hyprolog --- an extension of Prolog with linear and intuitionistic logic and with abduction; and b) a customisable extension of PGs that lets us model also concepts and relations to some degree. We exemplify within the domain of extracting concepts from biomedical text.
    [bibtex-key = dahl_gu_maharshak_hyprolog_pgs_iwann09]
  346. Verónica Dahl and Erez Maharshak. DNA Replication as a Model for Computational Linguistics. In IWINAC '09: Proc. Third Intl. Work-Conf. on the Interplay Between Natural and Artificial Computation, LNCS, pages 346-355, 2009. SV. [doi:10.1007/978-3-642-02264-7_36] Keyword(s): linguistics.
    Abstract:
    We examine some common threads between biological sequence analysis and AI methods, and propose a model of human language processing inspired in biological sequence replication and nucleotide bindings. It can express and implement both analysis and synthesis in the same stroke, much as biological mechanisms can analyse a string plus synthesize it elsewhere, e.g. for repairing damaged DNA substrings.
    [bibtex-key = dahl_maharshak_dna_replication_iwinac09]
  347. Leslie De Koninck. Execution control for Constraint Handling Rules -- PhD Summary. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 479-483, July 2009. SV. [doi:10.1007/978-3-642-02846-5_38] Keyword(s): priorities. [bibtex-key = dekoninck_phdsummary_iclp09]
  348. François Degrave, Tom Schrijvers, and Wim Vanhoof. Automatic generation of test inputs for Mercury. In M. Hanus, editor, LOPSTR08l, volume 5438 of LNCS, 2009. SV. [doi:10.1007/978-3-642-00515-2] Keyword(s): applications, testing.
    Abstract:
    In this work, we consider the automatic generation of test inputs for Mercury programs. We use an abstract representation of a program that allows to reason about program executions as paths in a control-flow graph. Next, we define how such a path corresponds to a set of constraints whose solution defines input values for the predicate under test such that when the predicate is called with respect to these input values, the execution is guaranteed to follow the given path. In our approach, we use CHR to solve the constraints and generate the corresponding test inputs. The method allows for algorithms constructing sets of paths (and hence the corresponding test inputs) guided by well-known test coverage criteria addressing structural properties of the code such as statement, branch or path coverage. The approach is similar to existing work for imperative languages, but has been considerably adapted to deal with the specificities of Mercury, such as symbolic data representation, predicate failure and non-determinism.
    [bibtex-key = degrave_schr_vanhoof_test_inputs_merc_lopstr08]
  349. Cinzia Di Giusto, Maurizio Gabbrielli, and Maria Chiara Meo. Expressiveness of Multiple Heads in CHR. In SOFSEM '09: Proc. 35th Conf. Current Trends in Theory and Practice of Comp. Science, LNCS, pages 205-216, 2009. SV. [doi:10.1007/978-3-540-95891-8_21] Keyword(s): expressivity.
    Abstract:
    Constraint Handling Rules (CHR) is a general purpose, committed-choice declarative language which, differently from other similar languages, uses multi-headed (guarded) rules. In this paper we prove that multiple heads augment the expressive power of the language. In fact, we first show that restricting to single head rules affects the Turing completeness of CHR, provided that the underlying signature (for the constraint theory) does not contain function symbols. Next we show that, also when considering generic constraint theories, under some rather reasonable assumptions it is not possible to encode CHR (with multi-headed rules) into a single-headed CHR language while preserving the semantics of programs. As a corollary we obtain that, under these assumptions, CHR can be encoded neither in (constraint) logic programming nor in pure Prolog.
    [bibtex-key = giustu_gabbri_meo_multiple_heads_sofsem09]
  350. Thom Frühwirth. First steps towards a lingua franca for computer science: Rule-based Approaches in CHR. In F. Raiser and J. Sneyers, editors, CHR09l, pages 1, July 2009. KULCW, Technical report CW 555. Note: Invited talk. [PDF] Keyword(s): CHR 2009, related formalisms, CHR 2009, CHR 2009. [bibtex-key = fru_lingua_franca_chr09]
  351. Maurizio Gabbrielli, Maria Chiara Meo, and Jacopo Mauro. On the expressive power of priorities in CHR. In F.J. López-Fraguas, editor, PPDP09l, pages 267-276, September 2009. ACM. [doi:10.1145/1599410.1599443] Keyword(s): expressivity, priorities.
    Abstract:
    Constraint Handling Rules (CHR) is a committed-choice declarative language which has been originally designed for writing constraint solvers and which is nowadays a general purpose language. Recently the language has been extended by introducing user-definable (static or dynamic) rule priorities. The resulting language, called CHR$^{rp}$, allows a better control over execution while retaining a declarative and flexible style of programming. In this paper we study the expressive power of this language from the view point of the concurrency theory. We first show that dynamic priorities do not augment the expressive power by providing an encoding of dynamic priorities into static ones. Then we show that, when considering the theoretical operational semantics, CHR$^{rp}$ is strictly more expressive than CHR. This result is obtained by using a problem similar to the leader-election to show that, under some conditions, there exists no encoding of CHR$^rp$ into CHR. We also show, by using a similar technique, that the CHR language with the, so called, refined semantics is more expressive power than CHR with theoretical semantics and we extend some previous results showing that CHR can not be encoded into Prolog.
    [bibtex-key = gabbrielli_meo_mauro_express_priorities_ppdp09]
  352. T. Gannon, S. Madnick, A. Moulton, M. Siegel, M. Sabbouh, and Hongwei Zhu. Framework for the Analysis of the Adaptability, Extensibility, and Scalability of Semantic Information Integration and the Context Mediation Approach. In IEEE 42nd Hawaii International Conference on System Sciences (HICSS '09), pages 1- 11, January 2009. [bibtex-key = gannon_hicss09]
  353. Marco Gavanelli, Marco Alberti, and Evelina Lamma. Integration of abductive reasoning and constraint optimization in SCIFF. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 387-401, July 2009. SV. [doi:10.1007/978-3-642-02846-5_32] Keyword(s): abduction.
    Abstract:
    Abductive Logic Programming (ALP) and Constraint Logic Programming (CLP) share the feature to constrain the set of possible solutions to a program via integrity or CLP constraints. These two frameworks have been merged in works by various authors, which developed efficient abductive proof-procedures empowered with constraint satisfaction techniques. However, while almost all CLP languages provide algorithms for finding an optimal solution with respect to some objective function (and not just {\em any} solution), the issue has received little attention in ALP. In this paper we show how optimisation meta-predicates can be included in abductive proof-pro\-ce\-dures, achieving in this way a significant improvement to research and practical applications of abductive reasoning. In the paper, we give the declarative and operational semantics of an abductive proof-procedure that encloses constraint optimization meta-predicates, and we prove soundness in the three-valued completion semantics. In the proof-procedure, the abductive logic program can invoke optimisation meta-predicates, which can invoke abductive predicates, in a recursive way.
    [bibtex-key = gavanelli_alberti_lamme_SCIFF_iclp09]
  354. Thierry Martinez. On connections between CHR and LCC. In F. Raiser and J. Sneyers, editors, CHR09l, pages 18-32, July 2009. KULCW, Technical report CW 555. [PDF] Keyword(s): CHR 2009, linear logic, related formalisms, CHR 2009, CHR 2009.
    Abstract:
    Both CHR and LCC languages are based on the same model of concurrent computation, where agents communicate through a shared constraint store, with a synchronization mechanism based on constraint entailment. The Constraint Simplification Rules (CSR) subset of CHR and the flat subset of LCC, where agent nesting is restricted, are very close syntactically and semantically. The first contribution of this paper is to provide translations between CSR and flat-LCC and back. The second contribution is a transformation from the full LCC language to flat-LCC lambda-lifting in functional languages. In conjunction with the equivalence between CHR and CSR with respect to naive operational semantics, these results lead to semantics-preserving translations from full LCC to CHR and conversely. Immediate consequences of this work include new proofs for CHR linear logic and phase semantics, relying on corresponding results lambda-calculus in CHR.
    [bibtex-key = martinez_lcc_chr09]
  355. Paolo Pilozzi. Automating termination proofs for CHR. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 504-508, July 2009. SV. [doi:10.1007/978-3-642-02846-5_43] Keyword(s): termination. [bibtex-key = pilozzi_auto_term_proofs_iclp09]
  356. Paolo Pilozzi. Proving termination by invariance relations. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 499-503, July 2009. SV. [doi:10.1007/978-3-642-02846-5_42] Keyword(s): termination. [bibtex-key = pilozzi_term_invar_rels_iclp09]
  357. Paolo Pilozzi. Research Summary: Termination of CHR. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 534-535, July 2009. SV. [doi:10.1007/978-3-642-02846-5_51] Keyword(s): termination. [bibtex-key = pilozzi_research_summary_iclp09]
  358. Frank Raiser. Research Summary: Analysing Graph Transformation Systems Using Extended Methods from Constraint Handling Rules. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 540-541, July 2009. SV. [doi:10.1007/978-3-642-02846-5_54] Keyword(s): Graph Transformation Systems, related formalisms. [bibtex-key = raiser_research_summary_iclp09]
  359. Frank Raiser, Hariolf Betz, and Thom Frühwirth. Equivalence of CHR States Revisited. In F. Raiser and J. Sneyers, editors, CHR09l, pages 33-48, July 2009. KULCW, Technical report CW 555. [PDF] Keyword(s): CHR 2009, semantics, CHR 2009, CHR 2009.
    Abstract:
    While it is generally agreed-upon that certain classes of CHR states should be considered equivalent, no standard definition of equivalence has ever been established. Furthermore, the compliance of equivalence with rule application is generally assumed, but has never been proven. We systematically develop an axiomatic notion of state equivalence based on rule applicability and the declarative semantics. We supply the missing proof for its compliance with rule application and provide a proof technique to determine equivalence of given states. The compliance property leads to a simplified formulation of the operational semantics. Furthermore, it justifies a novel view based on equivalence classes of states which provides a powerful proof technique.
    [bibtex-key = raiser_betz_fru_equivalence_revisited_chr09]
  360. Frank Raiser and Thom Frühwirth. Operational Equivalence of Graph Transformation Systems. In F. Raiser and J. Sneyers, editors, CHR09l, pages 49-61, July 2009. KULCW, Technical report CW 555. [PDF] Keyword(s): CHR 2009, Graph Transformation Systems, related formalisms, CHR 2009, CHR 2009.
    Abstract:
    Graph transformation systems (GTS) provide an important theory for numerous applications. With the growing number of GTS-based applications the comparison of operational equivalence of two GTS becomes an important area of research. This work introduces a notion of operational equivalence for graph transformation systems. The embedding of GTS in constraint handling rules (CHR) provides the basis for a decidable and sufficient criterion for operational equivalence of GTS. It is based on the operational equivalence test for CHR programs. A direct application of adapting this test to GTS allows automatic removal of redundant rules.
    [bibtex-key = raiser_fru_oper_equiv_gts_chr09]
  361. Frank Raiser and Thom Frühwirth. Strong joinability analysis for graph transformation systems in CHR. In TERMGRAPH '09: Proc. 5th Intl. Workshop on Computing with Terms and Graphs, pages 97-112, March 2009. Keyword(s): Graph Transformation Systems, related formalisms. [bibtex-key = raiser_fruh_joinabil_graph_transf_termgraph09]
  362. Beata Sarna-Starosta and Tom Schrijvers. Attributed Data for CHR Indexing. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 357-371, July 2009. SV. [doi:10.1007/978-3-642-02846-5_30] Keyword(s): implementation, optimizing compilation. [bibtex-key = ss_schr_attr_data_iclp09]
  363. Jon Sneyers. Optimizing Compilation and Computational Complexity of Constraint Handling Rules -- Ph.D. thesis summary. In Patricia M. Hill and David S. Warren, editors, ICLP09l, volume 5649 of LNCS, pages 494-498, July 2009. SV. [doi:10.1007/978-3-642-02846-5_41] Keyword(s): implementation, optimizing compilation, complexity, computability. [bibtex-key = sneyers_phdsummary_iclp09]
  364. Jon Sneyers, Wannes Meert, and Joost Vennekens. CHRiSM: Chance Rules induce Statistical Models. In F. Raiser and J. Sneyers, editors, CHR09l, pages 62-76, July 2009. KULCW, Technical report CW 555. [PDF] Keyword(s): CHR 2009, probabilistic CHR, CHRiSM, extensions , CHR 2009, CHR 2009.
    Abstract:
    A new probabilistic-logic formalism, called CHRiSM, is introduced. CHRiSM is based on a combination of CHR and PRISM. It can be used for high-level rapid prototyping of complex statistical models by means of chance rules. The underlying PRISM system can then be used for several probabilistic inference tasks, including parameter learning. We describe a source-to-source transformation from CHRiSM rules to PRISM, via CHR(PRISM). Finally we discuss the relation between CHRiSM and probabilistic logic programming, in particular, CP-logic.
    [bibtex-key = sneyers_meert_vennekens_chrism_chr09]
  365. Peter Van Weert, Leslie De Koninck, and Jon Sneyers. A Proposal for a Next Generation of CHR. In F. Raiser and J. Sneyers, editors, CHR09l, pages 77-93, July 2009. KULCW, Technical report CW 555. [PDF] Keyword(s): CHR 2009, semantics, priorities, extensions, CHR 2009, CHR 2009.
    Abstract:
    This is a proposal for a next generation of CHR called CHR2. It combines the best features of language extensions proposed in earlier work and offers a solution to their main drawbacks. We introduce several novel language features, designed to allow the flexible, high-level specification of readable, efficient programs. Moreover, CHR2 is backwards compatible, such that existing programs can make use of CHR2’s new features, but do not need to be changed.
    [bibtex-key = vanweert_dekoninck_sneyers_chr2_chr09]
  366. Slim Abdennadher and Shehab Fawzy. JCHRIDE: An Integrated Development Environment for JCHR. In Sibylle Schwarz, editor, WLP '08: Proc. 22nd Workshop on (Constraint) Logic Programming, Dresden, Germany, pages 1-6, September 2008. University Halle-Wittenberg, Institute of Computer Science, Technical report 2008/08. Keyword(s): Java.
    Abstract:
    The rule-based programming language Constraint Handling Rules (CHR) has been introduced to ease the development and implementation of constraint solvers. Currently, several CHR libraries exist in languages such as Prolog, Haskell and Java. The K.U.Leuven JCHR system is a high-performance integration of Constraint Handling Rules (CHR) and Java. JCHR is currently by far the most efficient implementation of CHR in Java. Its performance is competitive with state-of-the-art CHR systems in e.g.\ HAL and Prolog. To ease the duty of a CHR programmer, we introduce in this paper an integrated development environment (IDE) for the K.U.Leuven JCHR. The IDE is implemented as a plug-in in Eclipse.
    [bibtex-key = abd_fawzy_jchride_wlp08]
  367. Slim Abdennadher and Ingi Sobhi. Generation of Rule-based Constraint Solvers: Combined Approach. In A. King, editor, LOPSTR07l, volume 4915 of LNCS, 2008. Keyword(s): program generation. [bibtex-key = abd_sobhi_generation_combined_lopstr07]
  368. Marcos Aurélio, François Fages, and Jacques Robin. Default Reasoning in CHR$^\vee$. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 111-126, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, disjunction, CHR 2008, CHR 2008.
    Abstract:
    CHR$^\vee$ has emerged as a versatile knowledge representation language, usable for an unparalleled variety of automated reasoning tasks: constraint solving, optimization, classification, subsumption, classical deduction, abduction, truth-maintenance, belief revision, belief update and planning. In this paper, we add default reasoning to this list, by showing how to represent default logic theories in CHR$^\vee$. We then discuss how to leverage this representation together with the well-know correspondence between default logic and Negation As Failure (NAF) in logic programming, to propose an extension CHR$^{\vee,naf}$ of CHR$^\vee$ allowing NAF in the rule heads.
    [bibtex-key = aurelio_fages_robin_defaultreasoning_chr08]
  369. Henning Christiansen. Prioritized Abduction with CHR. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 159-173, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, abduction, priorities, probabilistic CHR, CHR 2008, CHR 2008.
    Abstract:
    A class of Prioritized Abductive Logic Programs (PrioALPs) is introduced and an implementation is developed in CHR for solving abductive problems, providing minimal explanations with best-first search. Priorities may represent probabilities or a cost function to be optimized. Compared with other weighted and probabilistic versions of abductive logic programming, the approach is characterized by higher generality and a flexible and adaptable architecture which incorporates integrity constraints and interaction with external constraint solvers. A PrioALP is translated in a systematic way into a CHR program which serves as a query interpreter, and the resulting CHR code describes in a highly concise way, the strategies applied in the search for explanations.
    [bibtex-key = christiansen_prioritizedabduction_chr08]
  370. Leslie De Koninck, Peter J. Stuckey, and Gregory J. Duck. Optimizing compilation of CHR with rule priorities. In J. Garrigue and M. Hermenegildo, editors, Proc. 9th Intl. Symp. Functional and Logic Programming, volume 4989 of LNCS, pages 32-47, April 2008. SV. Keyword(s): priorities, optimizing compilation. [bibtex-key = dekoninck_stuck_duck_compiling-chrrp_flops08]
  371. Gregory J. Duck, Leslie De Koninck, and Peter J. Stuckey. Cadmium: An Implementation of ACD Term Rewriting. In M. Garcìa de la Banda and E. Pontelli, editors, ICLP08l, volume 5366 of LNCS, pages 531-545, December 2008. SV. [doi:10.1007/978-3-540-89982-2] Keyword(s): implementation. [bibtex-key = duck_cadmium_iclp08]
  372. François Fages, Cleyton Mário de Oliveira Rodrigues, and Thierry Martinez. Modular CHR with phask and phtell. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 95-110, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, CHR 2008, CHR 2008.
    Abstract:
    In this paper, we introduce a modular version of the Constraint Handling Rules language CHR, called CHRat for modular CHR with \emph{ask} and \emph{tell}. Any constraint defined in a CHRat component can be reused both in rules and guards in another CHRat component to define new constraint solvers. Unlike previous work on modular CHR, our approach is completely general as it does not rely on an automatic derivation of conditions for checking entailment in guards, but on a programming discipline for defining both satisfiability (\emph{tell}) and entailment (\emph{ask}) checks by CHRat rules for each constraint. We define the operational and declarative semantics of CHRat, provide a transformation of CHRat components to flat CHR programs, and prove the preservation of the semantics. We then provide examples of the modularization of classical CHR constraint solvers and of the definition of complex constraint solvers in a modular fashion.
    [bibtex-key = fages_et_al_modularchr_chr08]
  373. Thom Frühwirth. Quasi-Linear-Time Algorithms by Generalisation of Union-Find in CHR. In Recent Advances in Constraints --- CSCLP '07: 12th ERCIM Intl. Workshop on Constraint Solving and Constraint Logic Programming, Revised Selected Papers, pages 91-118, November 2008. [doi:10.1007/978-3-540-89812-2_7] Keyword(s): algorithms.
    Abstract:
    The union-find algorithm can be seen as solving simple equations between variables or constants. With a few lines of code change, we generalise its implementation in CHR from equality to arbitrary binary relations. By choosing the appropriate relations, we can derive fast incremental algorithms for solving certain propositional logic (SAT) problems and polynomial equations in two variables. In general, we prove that when the relations are bijective functions, our generalisation yields a correct algorithm. We also show that bijectivity is a necessary condition for correctness if the relations include the identity function. The rules of our generic algorithm have additional properties that make them suitable for incorporation into constraint solvers: from classical union-find, they inherit a compact solved form and quasi-linear time and space complexity. By nature of CHR, they are anytime and online algorithms. They solve and simplify the constraints in the problem, and can test them for entailment, even when the constraints arrive incrementally.
    [bibtex-key = fru_general_union_find_csclp07]
  374. Marco Gavanelli, Marco Alberti, and Evelina Lamma. Integrating Abduction and Constraint Optimization in Constraint Handling Rules. In ECAI 2008: 18th European Conf. on Artif. Intell., pages 903-904, July 2008. IOS press. [doi:10.3233/978-1-58603-891-5-903] Keyword(s): abduction. [bibtex-key = gavanelli_alberti_lamma_abduction_optimization_ecai08]
  375. Rémy Haemmerlé and Hariolf Betz. Verification of Constraint Handling Rules using Linear Logic Phase Semantics. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 67-78, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, linear logic, verification, CHR 2008, CHR 2008.
    Abstract:
    Constraint Handling Rules (CHR) is a declarative concurrent programming language. Like the class of Concurrent Constraint (CC) languages, CHR features a declarative semantics based on Girard's intuitionistic linear logic. The phase semantics of linear logic has been used in the past to prove safety properties for the class of CC languages. In this paper we show that we can adapt this result to prove safety properties for CHR as well.
    [bibtex-key = haemerle_betz_verificationlinearlogicphase_chr08]
  376. Edmund S.L. Lam and Martin Sulzmann. Finally, A Comparison Between Constraint Handling Rules and Join-Calculus. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 51-66, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, related formalisms, CHR 2008, CHR 2008.
    Abstract:
    We provide a comparison between Constraint Handling Rules and Join-Calculus. Constraint Handling Rules is a concurrent constraint programming language originally designed for writing constraint solvers. Join-Calculus is a process calculus designed to provide the programmer with expressive concurrency abstraction. The semantics of both calculi is based on the Chemical Abstract Machine. Hence, we expect that both calculi share some commonalities. Surprisingly, both calculi have thus far been studied independently, yet we believe that a comparison of these two independent fields of study is long overdue. This paper establishes a first bridge between Constraint Handling Rules and Join-Calculus as a basis for future explorations. Specifically, we provide examples showing that Join-Calculus can benefit from guarded constraints and constraint propagation as found in Constraint Handling Rules. We provide a compilation scheme for such an enriched Join-Calculus by applying the constraint matching methods of the refined operational Constraint Handling Rules semantics.
    [bibtex-key = lam_sulz_finallyjoin_chr08]
  377. Paolo Pilozzi and Danny De Schreye. Termination Analysis of CHR Revisited. In M. Garcìa de la Banda and E. Pontelli, editors, ICLP08l, volume 5366 of LNCS, pages 501-515, December 2008. SV. [doi:10.1007/978-3-540-89982-2_43] Keyword(s): termination.
    Abstract:
    Today, two distinct direct approaches to prove termination of CHR programs exist. The first approach, by T. Fr\"uhwirth, proves termination of CHR programs without propagation. The second, by Voets et al., deals with programs that contain propagation. It is however less powerful on programs without propagation. In this paper, we present new termination conditions that are strictly more powerful than those from previous approaches and that are also applicable to a new class of programs. Furthermore, we present a new representation for CHR states for which size-decreases between consecutive states correspond to termination. Both contributions are linked: our termination conditions correspond to the existence of a well-founded order on the new state representation, which decreases for consecutive computation states.
    [bibtex-key = pilozzi_deschreye_termination_revisited_iclp08]
  378. Paolo Pilozzi and Danny De Schreye. Termination Analysis of CHR revisited. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 35-50, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, termination, CHR 2008, CHR 2008.
    Abstract:
    Today, there exist two distinct direct approaches to prove termination of CHR programs. Both are applicable on separate classes of CHR programs. One approach, by T. Fr{\"u}hwirth, proves termination of CHR programs without propagation rules. A second approach deals with CHR programs with propagation rules. Due to its extended scope to such programs, it fails to prove termination for a class of CHR programs without propagation that are in the scope of Fr{\"u}hwirth's approach. In this paper, we introduce a termination condition for CHR which is strictly more powerful than both of these and deals with a new class of programs.
    [bibtex-key = pilozzi_deschreye_terminationrevisited_chr08]
  379. Frank Raiser. Semi-automatic generation of CHR solvers from global constraint automata. In Peter J. Stuckey, editor, CP08l, volume 5202 of LNCS, pages 588-592, September 2008. SV. [doi:10.1007/978-3-540-85958-1_47] Keyword(s): program generation.
    Abstract:
    Constraint programming often involves global constraints, for which various custom filtering algorithms have been published. This work presents a semi-automatic generation of CHR solvers for the subset of global constraints defineable by specific automata. The generation is based on a constraint logic program modelling an automaton and an improved version of the Prim-Miner algorithm. The solvers only need to be generated once and achieve arc-consistency for over 40 global constraints.
    [bibtex-key = raiser_globalconstraintautomata_cp08]
  380. Frank Raiser and Thom Frühwirth. Towards Term Rewriting Systems in Constraint Handling Rules. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 19-34, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): related formalisms, CHR 2008, CHR 2008, CHR 2008.
    Abstract:
    Term rewriting systems are a formalism in widespread use, often implemented by means of term graph rewriting. In this work we present preliminary results towards an elegant embedding of term graph rewriting in Constraint Handling Rules with rule priorities ($\mathrm{CHR}^\mathrm{rp}$). As term graph rewriting is well-known to be incomplete with respect to term rewriting, we aim for sound jungle evaluation in $\mathrm{CHR}^\mathrm{rp}$. Having such an embedding available allows to benefit from CHR's online property and parallelization potential.
    [bibtex-key = raiser_fru_towardstermrewriting_chr08]
  381. Beata Sarna-Starosta and Tom Schrijvers. An efficient term representation for CHR indexing. In M. Carro and B. Demoen, editors, CICLOPS '08: Proc. 8th Colloquium on Implementation of Constraint and LOgic Programming Systems, pages 172-186, 2008. Keyword(s): implementation, optimizing compilation. [bibtex-key = sss_term_indexing_ciclops08]
  382. Beata Sarna-Starosta and Tom Schrijvers. Transformation-based Indexing Techniques for Constraint Handling Rules. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 3-18, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): implementation, optimizing compilation, CHR 2008, CHR 2008, CHR 2008.
    Abstract:
    Multi-headed rules are essential for the expressiveness of Constraint Handling Rules (CHR), but incur considerable performance overhead. Current indexing techniques are often unable to address this problem—they require matchings to have particular form, or offer good run-time complexity rather than good absolute figures. We introduce two lightweight program transformations, based on term flattening, which improve the effectiveness of existing CHR indexing techniques, in terms of both complexity and constant factors. We also describe a set of complementary post-processing program transformations, which considerably reduce the flattening overhead. We compare our techniques with the current state of the art in CHR compilation, and measure their efficacy in K.U.Leuven CHR and CHRd.
    [bibtex-key = sarnastarosta_schr_transform_indexing_chr08]
  383. Beata Sarna-Starosta, David Zook, Emir Pasalic, and Molham Aref. Relating Constraint Handling Rules to Datalog. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 127-142, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, related formalisms, CHR 2008, CHR 2008.
    Abstract:
    Datalog$^ extsc{LB}$ is an extension of Datalog supporting global stratification of negation and functional dependencies, designed for use in industrial-scale decision automation applications. Constraint Handling Rules (CHR) is a declarative rule-based programming language, particularly suitable for specifying custom constraint solvers at a high level. Our goal is to enhance Datalog$^ extsc{LB}$ with CHR-like capabilities in order to improve its expressive power and open it to specification of general-purpose constraint solvers for industrial applications. In this paper we relate the two formalisms and define a translation of a significant class of CHR programs into Datalog$^ extsc{LB}$. It turns out that the translation enables reasoning about the properties of CHR programs at a high level of Datalog logic.
    [bibtex-key = sarnastarosta_pasalic_datalog_chr08]
  384. Anders Schack-Nielsen and Carsten Schürmann. The CHR-Celf Connection. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 1-2, 2008. RISC Report Series 08-10, University of Linz, Austria. Note: Invited Talk. [PDF] Keyword(s): CHR 2008, related formalisms, CHR 2008, CHR 2008.
    Abstract:
    Celf is a meta-language for specifying and implementing deductive and concurrent systems from areas, such as programming language theory, process algebras, and logics. It is based on the concurrent logical framework CLF. The Constraint Handling Rules (CHR) language is a major specification and implementation language for constraint-based algorithms. In this invited talk, we give a tutorial-style introduction to Celf for the CHR programmer where we highlight some of Celf's features including the support of higher-order encodings, first-class execution traces, and a logically inspired proof search semantics. Furthermore we show where the semantics of the two languages coincide.
    [bibtex-key = sch_sch_chrcelf_chr08]
  385. Tom Schrijvers. Constraint Handling Rules --- A Tutorial for (Prolog) Programmers. In M. Garcìa de la Banda and E. Pontelli, editors, ICLP08l, volume 5366 of LNCS, pages 9-10, December 2008. SV. [doi:10.1007/978-3-540-89982-2_3] Keyword(s): tutorial. [bibtex-key = schr_tutorial_iclp08]
  386. Tom Schrijvers and Martin Sulzmann. Restoring confluence for functional dependencies. In Draft Proc. 9th Symp. Trends in Funct. Programming, Nijmegen, pages 22-36, May 2008. Radbound University. Keyword(s): type systems, confluence.
    Abstract:
    Functional dependencies provide for a relational specification of user-programmable type improvement connected to type class instances. On the other hand, the more recent type families (also known as type functions) equip the programmer with a functional specification for user-programmable type improvement decoupled from type class instances. Functional dependencies are supported by both GHC and Hugs, while the most recent version of GHC also supports type functions. There is an enthusiastic and lively debate which feature shall make it into the next Haskell standard, Haskell-Prime. Currently, further progress in the standardization appears to be stalled on this issue. In this paper, we attempt to rekindle the debate with new insights in type inference issues behind functional dependencies (FDs) and type functions (TFs), without taking sides.
    [bibtex-key = schr_sulz_restoring_confl_fd_tfp08]
  387. Tom Schrijvers and Martin Sulzmann. Transactions in Constraint Handling Rules. In M. Garcìa de la Banda and E. Pontelli, editors, ICLP08l, volume 5366 of LNCS, pages 516-530, December 2008. SV. [doi:10.1007/978-3-540-89982-2_44] Keyword(s): parallelism.
    Abstract:
    CHR is a highly concurrent language, and yet it is by no means a trivial task to write correct concurrent CHR programs. We propose a new semantics for CHR, which allows specifying and reasoning about transactions. Transactions alleviate the complexity of writing concurrent programs by offering entire derivations to run atomically and in isolation. We derive several program transformations based on our semantics that transform particular classes of transitional CHR programs to non-transactional ones. These transformations are useful because they obviate a general purpose transaction manager, and may lift unnecessary sequentialization present in the transactional semantics.
    [bibtex-key = schr_sulz_transactions_iclp08]
  388. Jon Sneyers. Turing-complete Subclasses of CHR. In M. Garcìa de la Banda and E. Pontelli, editors, ICLP08l, volume 5366 of LNCS, pages 759-763, December 2008. SV. [doi:10.1007/978-3-540-89982-2_72] Keyword(s): computability. [bibtex-key = sneyers_subclass_iclp08]
  389. Jon Sneyers and Thom Frühwirth. Generalized CHR Machines. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 143-158, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, complexity, CHR 2008, CHR 2008.
    Abstract:
    Constraint Handling Rules (CHR) is a high-level rule-based programming language. In earlier work, a model of computation based on the operational semantics of CHR called the CHR machine was introduced. The CHR machine was used to prove a complexity-wise completeness result for the CHR language and its implementations. In this paper, we investigate three generalizations of CHR machines: CHR machines with an instantiated operational semantics, non-deterministic CHR machines, and self-modifying CHR machines.
    [bibtex-key = sneyers_fru_generalizedmachines_chr08]
  390. Martin Sulzmann and Duc Hiep Chu. A Rule-Based Specification of Software Transactional Memory. In M. Hanus, editor, LOPSTR08prel, 2008. [WWW] [PDF] Keyword(s): parallelism.
    Abstract:
    Software Transactional Memory (STM) has the promise to avoid the common pitfalls of locks when writing thread-based concurrent programs. Many papers on the subject deal with low-level implementation details to support the efficient and concurrent execution of multiple transactions.We give a rule-based specification of Software Transactional Memory in terms of Constraint Handling Rules (CHR) which naturally supports the concurrent execution of transactions. Such a high-level description of STM in terms of CHR has the advantage that we can easier understand the workings of STM and we can better analyze and verify STM. We verify correctness of a particular CHR-based STM implementation.
    [bibtex-key = sulzm_chu_lopstr08]
  391. Martin Sulzmann and Edmund S.L. Lam. Parallel execution of multi-set constraint rewrite rules. In S. Antoy, editor, PPDP08l, pages 20-31, July 2008. ACM. [doi:10.1145/1389449.1389453] Keyword(s): parallelism. [bibtex-key = sulz_lam_parallelexecution_ppdp08]
  392. Martin Sulzmann, Edmund S.L. Lam, and Peter Van Weert. Actors with Multi-Headed Message Receive Patterns. In D. Lea and G. Zavattaro, editors, COORDINATION '08: Proc. 10th Intl. Conf. Coordination Models and Languages, number 5052 of LNCS, pages 315-330, May 2008. SV. [doi:10.1007/978-3-540-68265-3_20] Keyword(s): parallelism.
    Abstract:
    The actor model provides high-level concurrency abstractions to coordinate simultaneous computations by message passing. Languages implementing the actor model such as Erlang commonly only support single-headed pattern matching over received messages. We propose and design an extension of Erlang style actors with receive clauses containing multi-headed message patterns. Patterns may be non-linear and constrained by guards. We provide a number of examples to show the usefulness of the extension. We also explore the design space for multi-headed message matching semantics, for example first-match and rule priority-match semantics. The various semantics are inspired by the multi-set constraint matching semantics found in Constraint Handling Rules. This provides us with a formal model to study actors with multi-headed message receive patterns. The system can be implemented efficiently and we have built a prototype as a library-extension to Haskell.
    [bibtex-key = sulz_lam_vanweert_actors_coordination08]
  393. Peter Van Weert. A Tale of Histories. In T. Schrijvers, F. Raiser, and T. Frühwirth, editors, CHR08l, pages 79-94, 2008. RISC Report Series 08-10, University of Linz, Austria. [PDF] Keyword(s): CHR 2008, implementation, optimizing compilation, CHR 2008, CHR 2008.
    Abstract:
    Constraint Handling Rules (CHR) is an elegant, high-level programming language based on multi-headed, forward chaining rules. A distinguishing feature of CHR are propagation rules. To avoid trivial non-termination, CHR implementations ensure a CHR rule is applied at most once with the same combination of constraints by maintaining a so-called propagation history. The performance impact of this history is often significant. We introduce two optimizations to reduce or even eliminate this overhead, and evaluate their implementation in two state-of-the-art CHR systems.
    [bibtex-key = vanweert_histories_chr08]
  394. Peter Van Weert. Optimization of CHR Propagation Rules. In M. Garcìa de la Banda and E. Pontelli, editors, ICLP08l, volume 5366 of LNCS, pages 485-500, December 2008. SV. [doi:10.1007/978-3-540-89982-2_42] Keyword(s): implementation, optimizing compilation.
    Abstract:
    Constraint Handling Rules (CHR) is an elegant, high-level programming language based on multi-headed, forward chaining rules. To ensure CHR propagation rules are applied at most once with the same combination of constraints, CHR implementations maintain a so-called propagation history. The performance impact of this history can be significant. We introduce several optimizations that, for the majority of CHR rules, eliminate this overhead. We formally prove their correctness, and evaluate their implementation in two state-of-the-art CHR systems.
    [bibtex-key = vanweert_histories_iclp08]
  395. Peter Van Weert, Jon Sneyers, and Bart Demoen. Aggregates for CHR through Program Transformation. In A. King, editor, LOPSTR07l, volume 4915 of LNCS, pages 59-73, 2008. [doi:10.1007/978-3-540-78769-3_5] Keyword(s): extensions. [bibtex-key = vanweert_sney_demoen_aggregates_lopstr07]
  396. Dean Voets, Paolo Pilozzi, and Danny De Schreye. A new approach to termination analysis of CHR. In M. Hanus, editor, LOPSTR08prel, 2008. [WWW] [PDF] Keyword(s): termination.
    Abstract:
    We present a new approach to termination analysis of Constraint Handling Rules (CHR). Unlike current approaches, our approach has no restrictions on the kind of rules in the CHR program. We propose a termination condition, that verifies conditions imposed on the dynamic process of adding constraints to the store, instead of a termination argument based on the comparison of sizes of consecutive computation states. We demonstrate the condition's applicability on a set of terminating CHR programs, using a prototype analyzer. This analyzer is the first in-language automated termination analyzer for CHR programs.
    [bibtex-key = voets_pilozzi_deschreye_termination_lopstr08]
  397. Hariolf Betz. Relating Coloured Petri Nets to Constraint Handling Rules. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 33-47, September 2007. [PDF] Keyword(s): CHR 2007, related formalisms, CHR 2007, CHR 2007.
    Abstract:
    Constraint Handling Rules (CHR) is a declarative rulebased concurrent committed-choice programming language. Petri nets are a well-known formalism for modeling and analysis of concurrent processes. We aim to develop a framework to exploit Petri nets as a tool for the modeling and analysis of CHR programs. In this paper, we show that place/transition nets can easily be embedded into CHR and we develop a translation of a significant segment of CHR into coloured Petri nets (CPN).
    [bibtex-key = betz_petri_nets_chr07]
  398. Hariolf Betz and Thom Frühwirth. A Linear-Logic Semantics for Constraint Handling Rules with Disjunction. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 17-31, September 2007. [PDF] Keyword(s): CHR 2007, semantics, linear logic, CHR 2007, CHR 2007.
    Abstract:
    We motivate and develop a linear logic declarative semantics for CHR$^\vee$, an extension of the CHR programming language that integrates concurrent committed choice with backtrack search and a predefined underlying constraint handler. We show that our semantics maps each of these aspects of the language to a distinct aspect of linear logic. We show how we can use this semantics to reason about derivations in CHR$^\vee$ and we present strong theorems concerning its soundness and completeness.
    [bibtex-key = betz_fru_linear_logic_chr_disj_chr07]
  399. Henning Christiansen and Christian Theil Have. From Use Cases to UML Class Diagrams using Logic Grammars and Constraints. In RANLP '07: Proc. Intl. Conf. Recent Adv. Nat. Lang. Processing, pages 128-132, September 2007. Keyword(s): applications, linguistics. [bibtex-key = christ_have_use_cases_to_uml_ranlp07]
  400. Verónica Dahl and Baohua Gu. A CHRG Analysis of ambiguity in Biological Texts. In CSLP '07: Proc. 4th Intl. Workshop on Constraints and Language Processing, August 2007. Note: Extended Abstract. Keyword(s): linguistics, applications. [bibtex-key = dahl_gu_chrg_amb_bio_texts_cslp07]
  401. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. The Correspondence Between the Logical Algorithms Language and CHR. In V. Dahl and I. Niemelä, editors, ICLP07l, volume 4670 of LNCS, pages 209-223, September 2007. SV. [doi:10.1007/978-3-540-74610-2_15] Keyword(s): related formalisms. [bibtex-key = dekoninck_schr_demoen_la-chr_iclp07]
  402. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. User-definable Rule Priorities for CHR. In M. Leuschel and A. Podelski, editors, PPDP07l, pages 25-36, July 2007. ACM. ISBN: 978-1-59593-769-8. [doi:10.1145/1273920.1273924] Keyword(s): priorities. [bibtex-key = dekoninck_schr_demoen_chrrp_ppdp07]
  403. Leslie De Koninck and Jon Sneyers. Join Ordering for Constraint Handling Rules. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 107-121, September 2007. [PDF] Keyword(s): optimizing compilation, CHR 2007, CHR 2007, CHR 2007.
    Abstract:
    Join ordering is the problem of finding cost optimal execution plans for matching multi-headed rules. In the context of Constraint Handling Rules, this topic has received limited attention so far, even though it is of great importance for efficient CHR execution. We present a formal cost model for joins and investigate the possibility of join optimization at runtime. We propose some heuristic approximations of the parameters of this cost model, for both the static and dynamic case. We discuss an O(n log n) optimization algorithm for the special case of acyclic join graphs. However, in general, join order optimization is an NP-complete problem. Finally, we identify some classes of cyclic join graphs that can be reduced to acyclic ones.
    [bibtex-key = dekoninck_sney_join_ordering_chr07]
  404. Khalil Djelloul, Thi-Bich-Hanh Dao, and Thom Frühwirth. Toward a first-order extension of Prolog's unification using CHR: a CHR first-order constraint solver over finite or infinite trees. In SAC '07: Proc. 2007 ACM Symp. Applied computing, pages 58-64, 2007. ACM. ISBN: 1-59593-480-4. [bibtex-key = djelloul_dao_fru_1st_order_extension_prolog_unification_sac07]
  405. Gregory J. Duck, Peter J. Stuckey, and Martin Sulzmann. Observable Confluence for Constraint Handling Rules. In V. Dahl and I. Niemelä, editors, ICLP07l, volume 4670 of LNCS, pages 224-239, September 2007. SV. [doi:10.1007/978-3-540-74610-2_16] Keyword(s): confluence. [bibtex-key = duck_stuck_sulz_observable_confluence_iclp07]
  406. Thom Frühwirth. Description Logic and Rules the CHR Way. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 49-61, September 2007. Note: Extended Abstract. [PDF] Keyword(s): related formalisms, CHR 2007, CHR 2007, CHR 2007.
    Abstract:
    The challenges of the Semantic Web endeavour in knowledge representation and reasoning prompted a wealth of research in combining description logic (DL) as ontology languages (e.g. OWL) with logic programming for rule-based reasoning. General issues of combining and integrating formalisms have to be faced such as the type of combination, conceptual simplicity and tractability. Even though constraint-based programming has a tradition of tackling these questions, constraint-based rule formalisms such as constraint logic programming, concurrent constraint programming, constraint databases and constraint handling rules (CHR) have not explicitely been considered for combination with DL yet. The same holds for concurrency, which is an essential characteristic of the internet, but to the best of our knowledge has not been related to DL so far. Since CHR is a very expressive declarative concurrent constraintbased programming language with optimal performance guarantee and other interesting properties, we explore in this speculative paper what a CHR-based approach would look like in comparison to recent approaches for integrating OWL and rules.
    [bibtex-key = fru_description_logic_chr07]
  407. Rémy Haemmerlé and François Fages. Abstract Critical Pairs and Confluence of Arbitrary Binary Relations. In RTA '07: Proc. 18th Intl. Conf. Term Rewriting and Applications, volume 4533 of LNCS, June 2007. SV. [doi:10.1007/978-3-540-73449-9_17] Keyword(s): confluence.
    Abstract:
    In a seminal paper, Huet introduced abstract properties of term rewriting systems, and the confluence analysis of terminating term rewriting systems by critical pairs computation. In this paper, we provide an abstract notion of critical pair for arbitrary binary relations and context operators. We show how this notion applies to the confluence analysis of various transition systems, ranging from classical term rewriting systems to production rules with constraints and partial control strategies, such as the Constraint Handling Rules language CHR. Interestingly, we show in all these cases that some classical critical pairs can be disregarded. The crux of these analyses is the ability to compute critical pairs between states built with general context operators, on which a bounded, not necessarily well-founded, ordering is assumed.
    [bibtex-key = haemm_fages_abstract_critical_pairs_rta07]
  408. Ben Krause and Tim Wahls. jmle: A Tool for Executing JML Specifications via Constraint Programming. In Formal Methods: Applications and Technology, volume 4346 of LNCS, pages 293-296, 2007. SV. [doi:10.1007/978-3-540-70952-7_19]
    Abstract:
    Formal specifications are more useful and easier to develop if they are executable. In this work, we describe a system for executing specifications written in the Java Modeling Language (JML) by translating them to constraint programs, which are then executed via the Java Constraint Kit (JCK). Our system can execute specifications written at a high level of abstraction, and the generated constraint programs are Java implementations of the translated specifications. Hence, they can be called directly from ordinary Java code.
    [bibtex-key = krause_wahls_jmle_fmics06]
  409. Edmund S.L. Lam and Martin Sulzmann. A Concurrent Constraint Handling Rules Semantics and its Implementation with Software Transactional Memory. In DAMP '07: Proc. ACM SIGPLAN Workshop on Declarative Aspects of Multicore Programming, January 2007. ACM. [WWW] Keyword(s): parallelism. [bibtex-key = lam_sulz_concurrent_chr_damp07]
  410. Martin Magnusson and Patrick Doherty. Deductive Planning with Temporal Constraints. In Eyal Amir, Vladimir Lifschitz, and Rob Miller, editors, Logical Formalizations of Commonsense Reasoning: Papers from the 2007 AAAI Spring Symposium, March 2007. AAAI Press. [bibtex-key = magnusson_doherty_deductive_planning_aaai07]
  411. Julien Martin and François Fages. From Business Rules to Constraint Programs in Warehouse Management Systems. In Doctoral programme of the 13th Intl. Conf. on Princ. and Pract. of Constraint Programming, 2007. Keyword(s): related formalisms. [bibtex-key = martin_fages_business_rules_cpdc07]
  412. Marc Meister. Concurrency of the preflow-push algorithm in Constraint Handling Rules. In CSCLP'07: Proc. 12th Intl. Workshop on Constraint Solving and Constraint Logic Programming, pages 160-169, 2007. Keyword(s): algorithms, parallelism. [bibtex-key = meister_preflowpush_csclp07]
  413. Marc Meister, Khalil Djelloul, and Jacques Robin. A Unified Semantics for Constraint Handling Rules in Transaction Logic. In C. Baral, G. Brewka, and J. S. Schlipf, editors, LPNMR '07: Proc. 9th Intl. Conf. Logic Programming and Nonmonotonic Reasoning, volume 4483 of LNCS, pages 201-213, May 2007. SV. [doi:10.1007/978-3-540-72200-7_18] Keyword(s): semantics. [bibtex-key = meister_djelloul_robin_transaction_logic_semantics_lpnmr07]
  414. Paolo Pilozzi, Tom Schrijvers, and Danny De Schreye. Proving termination of CHR in Prolog: A transformational approach. In WST '07: 9th Intl. Workshop on Termination, June 2007. Keyword(s): termination. [bibtex-key = pilozzi_schr_deschreye_termination_wst07]
  415. Frank Raiser. Graph Transformation Systems in CHR. In V. Dahl and I. Niemelä, editors, ICLP07l, volume 4670 of LNCS, pages 240-254, September 2007. SV. [doi:10.1007/978-3-540-74610-2_17] Keyword(s): Graph Transformation Systems, related formalisms. [bibtex-key = raiser_graph_transformation_systems_iclp07]
  416. Frank Raiser and Paolo Tacchella. On Confluence of Non-terminating CHR Programs. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 63-76, September 2007. [PDF] Keyword(s): CHR 2007, confluence, CHR 2007, CHR 2007.
    Abstract:
    Confluence is an important property for any kind of rewrite system including CHR, which is a general-purpose declarative committedchoice language consisting of multi-headed guarded rules. CHR can yield a confluence problem, because of non-determinism in the choice of rules using the abstract semantics. Confluence in CHR is an ongoing research topic, because it provides numerous benefits for implementations. However, for non-terminating CHR programs confluence is generally undecidable. In this paper we apply the so-called Strong Church-Rosser property to CHR. This allows determination of confluence for a subset of non-terminating CHR programs.
    [bibtex-key = raiser_tacchella_confluence_non_terminating_chr07]
  417. Beata Sarna-Starosta and C.R. Ramakrishnan. Compiling Constraint Handling Rules for Efficient Tabled Evaluation. In M. Hanus, editor, PADL '07: Proc. 9th Intl. Symp. Practical Aspects of Declarative Languages, volume 4354 of LNCS, pages 170-184, January 2007. SV. [doi:10.1007/978-3-540-69611-7_11] Keyword(s): implementation. [bibtex-key = sarnastarosta_ramakrishnan_chrd_padl07]
  418. Stephan Schiffel and Michael Thielscher. Fluxplayer: A Successful General Game Player. In AAAI '07: Proc. 22nd AAAI Conf. Artificial Intelligence, pages 1191-1196, July 2007. AAAI Press. Keyword(s): FLUX. [bibtex-key = schiffel_thielscher_fluxplayer_aaai07]
  419. Jon Sneyers, Peter Van Weert, and Tom Schrijvers. Aggregates for Constraint Handling Rules. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 91-105, September 2007. [PDF] Keyword(s): CHR 2007, extensions, CHR 2007, CHR 2007.
    Abstract:
    We extend the Constraint Handling Rules language with aggregates such as sum, count, findall, and min. The proposed extension features nested aggregate expressions over guarded conjunctions of constraints, a series of predefined aggregates, and application-tailored user-defined aggregates. We formally define the operational semantics of aggregates, and show how incremental aggregate computation facilitates efficient implementations. Case studies demonstrate that language support for aggregates significantly reduces program size, thus improving readability and maintainability considerably.
    [bibtex-key = sney_vanweert_demoen_aggregates_chr07]
  420. Jon Sneyers, Peter Van Weert, Tom Schrijvers, and Bart Demoen. Aggregates in Constraint Handling Rules: Extended Abstract. In V. Dahl and I. Niemelä, editors, ICLP07l, volume 4670 of LNCS, pages 446-448, September 2007. SV. [doi:10.1007/978-3-540-74610-2_39] Keyword(s): extensions. [bibtex-key = sney_vanweert_schr_demoen_aggregates_iclp07]
  421. Martin Sulzmann and Edmund S.L. Lam. Compiling Constraint Handling Rules with Lazy and Concurrent Search Techniques. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 139-149, September 2007. [PDF] Keyword(s): CHR 2007, parallelism, CHR 2007, CHR 2007.
    Abstract:
    Constraint Handling Rules (CHR) is a concurrent commited choice constraint programming language to describe transformations (rewritings) among multi-sets of constraints. One of the main CHR execution tasks is the search for constraints matching a rule head. Several optimization techniques have been widely studied, yet the actual details of the search strategies and their implementation are rarely the center of attention. In this paper, we explore the implementation of several search strategies using the lazy functional language Haskell. In combination with concurrency abstractions as supported by the Glasgow Haskell Compiler we obtain very clean and efficient implementations for searching of matching constraints.
    [bibtex-key = sulz_lam_lazy_concurr_search_chr07]
  422. Martin Sulzmann and Edmund S.L. Lam. Haskell - Join - Rules. In Olaf Chitil, editor, IFL '07: 19th Intl. Symp. Implementation and Application of Functional Languages, pages 195-210, September 2007. Keyword(s): related formalisms. [bibtex-key = sulz_lam_haskelljoinrules_ifl07]
  423. Martin Sulzmann and Meng Wang. Aspect-oriented programming with type classes. In Proceedings of the 6th workshop on Foundations of aspect-oriented languages, FOAL '07, pages 65-74, 2007. ACM. ISBN: 978-1-59593-671-4. [WWW] Keyword(s): type systems. [bibtex-key = Sulzmann:2007:APT:1233833.1233842]
  424. Paolo Tacchella, Maurizio Gabbrielli, and Maria Chiara Meo. Unfolding in CHR. In M. Leuschel and A. Podelski, editors, PPDP07l, pages 179-186, July 2007. ACM. ISBN: 978-1-59593-769-8. [bibtex-key = tacchella_gabbrielli_meo_unfolding_ppdp07]
  425. Dean Voets, Paolo Pilozzi, and Danny De Schreye. A new approach to termination analysis of Constraint Handling Rules. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 77-89, September 2007. [PDF] Keyword(s): CHR 2007, termination, CHR 2007, CHR 2007.
    Abstract:
    We present a new approach to termination analysis of Constraint Handling Rules. The approach, compared to existing approaches, is applicable to a much larger class of CHR programs. A new termination condition is formulated, that instead of a termination argument based on the comparison of sizes of consecutive computation states, verifies conditions imposed on the dynamic process of adding constraints to the store. The condition's applicability to CHR programs, with rules not only of the simplification type, has been successfully tested, using a semi-automated analyzer.
    [bibtex-key = voets_pilozzi_deschreye_termination_chr07]
  426. Armin Wolf, Jacques Robin, and Jairson Vitorino. Adaptive CHR meets CHR$^{\lor}$: An Extended Refined Operational Semantics for CHR$^{\lor}$ Based On Justifications. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 1-15, September 2007. [PDF] Keyword(s): semantics, disjunction, CHR 2007, CHR 2007, CHR 2007.
    Abstract:
    Adaptive constraint processing with Constraint Handling Rules (CHR) allows the application of intelligent search strategies to solve Constraint Satisfaction Problems (CSP), but these search algorithms have to be implemented in the host language of adaptive CHR, which is currently Java. On the other hand, CHR$^\vee$ enables to explicitly formulate search in CHR, using disjunctive bodies to model choices. However, a naive implementation for handling disjunctions, in particular chronological backtracking (as implemented in Prolog) might cause "thrashing" due to an inappropriate order of decisions. To avoid this, a first combination of adaptive CHR and CHR$^\vee$ is presented to offer a more efficient embedded search mechanism to handle disjunctions. Therefore the refined operational semantics of CHR is extended for disjunctions and adaptation.
    [bibtex-key = wolf_robin_vitorino_adaptive_chr_or_chr07]
  427. Pieter Wuille, Tom Schrijvers, and Bart Demoen. CCHR: the fastest CHR Implementation, in C. In K. Djelloul, G. J. Duck, and M. Sulzmann, editors, CHR07l, pages 123-137, September 2007. [WWW] [PDF] Keyword(s): CHR 2007, implementation, CHR 2007, CHR 2007.
    Abstract:
    CHR is usually compiled to high-level languages (like Prolog) that make it hard or impossible to express low-level optimizations. This is a pity, because it confines CHR to be a prototyping language only, with an unacceptable performance for production quality software. This paper presents CCHR, a CHR system embedded in the C programming language, that compiles to low-level C code which is highly suitable for fine-grained performance improvements. In this way CCHR program performance comes close to matching that of native C, and easily outperforms other CHR implementations.
    [bibtex-key = wuille_schr_demoen_cchr_chr07]
  428. Slim Abdennadher, Abdellatif Olama, Noha Salem, and Amira Thabet. ARM: Automatic Rule Miner. In LOPSTR06, volume 4407 of LNCS, July 2006. SV. Keyword(s): program generation. [bibtex-key = abd_et_al_arm_lopstr06]
  429. Dulce Aguilar-Solis. Learning Semantic Parsers: A Constraint Handling Rule Approach. In S. Etalle and M. Truszczynski, editors, ICLP06l, volume 4079 of LNCS, pages 447-448, August 2006. SV. Note: Poster Paper. [doi:10.1007/11799573_42] Keyword(s): applications, linguistics.
    Abstract:
    Semantic parsing is the process of mapping a natural language input into some structure representing its meaning. Even though this process is natural and smooth for human beings, it constitutes a huge problem for a machine. Semantic parsing is a challenging and interesting problem that has been severely understudied. Most of the research in natural language understanding has focused on shallow semantic analysis (i.e. word sense disambiguation, case-role analysis, etc). Previous approaches to semantic parsing are not robust enough or are limited in its applicability because they are applied to simple domains where semantic parsing reduces to filling slots on a frame.
    [bibtex-key = aguilar_solis_semantic_parsing_iclp06]
  430. Susan E. Brennan, Klaus Mueller, Greg Zelinsky, IV Ramakrishnan, David S. Warren, and Arie Kaufman. Toward a Multi-Analyst, Collaborative Framework for Visual Analytics. In 2006 IEEE Symposium On Visual Analytics Science And Technology, October-November 2006. [bibtex-key = brennan_visual_analytics_06]
  431. Henning Christiansen. On the Implementation of Global Abduction. In Katsumi Inoue, Ken Satoh, and Francesca Toni, editors, CLIMA '06: 7th Intl. Workshop on Computational Logic in Multi-Agent Systems -- Revised, Selected and Invited Papers, volume 4371 of LNCS, pages 226-245, May 2006. SV. Keyword(s): abduction. [bibtex-key = christiansen_clima06]
  432. Verónica Dahl and Baohua Gu. Semantic Property Grammars for Knowledge Extraction from Biomedical Text. In S. Etalle and M. Truszczynski, editors, ICLP06l, volume 4079 of LNCS, pages 442-443, August 2006. SV. Note: Poster Paper. [doi:10.1007/11799573_40] Keyword(s): applications, linguistics.
    Abstract:
    We present \emph{Semantic Property Grammars}, designed to extract concepts and relations from biomedical texts. The implementation adapts a CHRG parser we designed for Property Grammars, which views linguistic constraints as properties between sets of categories and solves them by constraint satisfaction, can handle incomplete or erroneous text, and extract phrases of interest selectively. We endow it with concept and relation extraction abilities as well.
    [bibtex-key = dahl_gu_property_gram_biomed_iclp06]
  433. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. INCLP($\mathbb{R}$) - Interval-based nonlinear constraint logic programming over the reals. In M. Fink, H. Tompits, and S. Woltran, editors, WLP '06: Proc. 20th Workshop on Logic Programming, T.U.Wien, Austria, INFSYS Research report 1843-06-02, pages 91-100, February 2006. Keyword(s): applications. [bibtex-key = dekoninck_schr_demoen_inclpr_wlp06]
  434. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. Search strategies in CHR(Prolog). In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 109-124, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, disjunction, CHR 2006, CHR 2006.
    Abstract:
    We extend the refined operational semantics of Constraint Handling Rules to support the implementation of different search strategies. Such search strategies are necessary to build efficient Constraint Logic Programming systems. This semantics is then further refined so that it is more suitable as a basis for a trailing based implementation. We propose a source to source transformation to implement breadth first search in CHR(Prolog): CHR with Prolog as a host language. Breadth first search is chosen because it exhibits the main difficulties in the implementation of search strategies, while being easy to understand. We evaluate our implementation and give directions for future work.
    [bibtex-key = dekoninck_schr_demoen_search_chr06]
  435. Gregory J. Duck, Peter J. Stuckey, and Sebastian Brand. ACD Term Rewriting. In S. Etalle and M. Truszczynski, editors, ICLP06l, volume 4079 of LNCS, pages 117-131, August 2006. SV. [doi:10.1007/11799573_11] Keyword(s): related formalisms.
    Abstract:
    In this paper we introduce Associative Commutative Distributive Term Rewriting (ACDTR), a rewriting language for rewriting logical formulae. ACDTR extends AC term rewriting by adding distribution of conjunction over other operators. Conjunction is vital for expressive term rewriting systems since it allows us to require that multiple conditions hold for a term rewriting rule to be used. ACDTR uses the notion of a ``conjunctive context'', which is the conjunction of constraints that must hold in the context of a term, to enable the programmer to write very expressive and targeted rewriting rules. ACDTR can be seen as a general logic programming language that extends Constraint Handling Rules and AC term rewriting. In this paper we define the semantics of ACDTR and describe our prototype implementation.
    [bibtex-key = duck_stuck_brand_acd_term_rewriting_iclp06]
  436. Gregory J. Duck, Peter J. Stuckey, and Martin Sulzmann. Observable Confluence for Constraint Handling Rules. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 61-76, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, confluence, CHR 2006, CHR 2006.
    Abstract:
    Constraint Handling Rules (CHRs) are a powerful rule based language for specifying constraint solvers. Critical for any rule based language is the notion of confluence, and for terminating CHRs there is a decidable test for confluence. But many CHR programs that in practice are confluent fail this confluence test. The problem is that the states that illustrate non-confluence are not reachable in practice. In this paper we introduce the notion of observable confluence, a weaker notion of confluence which takes into account whether states are observable. We show for an important class of non-confluent programs arising from Haskell type class programs with functional dependencies, that they are observable confluent.
    [bibtex-key = duck_stuckey_sulzmann_observable_confl_chr06]
  437. Thom Frühwirth. Complete Propagation Rules for Lexicographic Order Constraints over Arbitrary Domains. In Recent Advances in Constraints --- CSCLP '05: Joint ERCIM/CoLogNET Intl. Workshop on Constraint Solving and CLP, Revised Selected and Invited Papers, volume 3978 of LNAI, 2006. SV. [bibtex-key = fru_lexico_csclp05:06]
  438. Thom Frühwirth. Constraint Handling Rules: the story so far. In A. Bossi and M.J. Maher, editors, PPDP06l, pages 13-14, July 2006. ACM. ISBN: 1-59593-388-3. Keyword(s): tutorial. [bibtex-key = fru_chr_story_so_far_ppdp06]
  439. Thom Frühwirth. Deriving Linear-Time Algorithms from Union-Find in CHR. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 49-60, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, algorithms, CHR 2006, CHR 2006.
    Abstract:
    The union-find algorithm can be seen as solving simple equations between variables or constants. With a few lines of code change, we generalise its implementation in CHR from equality to arbitrary binary relations. By choosing the appropriate relations, we can derive fast algorithms for solving certain propositional logic (SAT) problems as well as certain polynomial equations in two variables. While linear-time algorithms are known to check satisfiability and to exhibit certain solutions of these problems, our algorithms are simple instances of the generic algorithm and have additional properties that make them suitable for incorporation into constraint solvers: From classical union-find, they inherit simplicity and quasi-linear time and space. By nature of CHR, they are anytime and online algorithms. They can be parallelised. They solve and simplify the constraints in the problem, and can test them for entailment, even when the constraints arrive incrementally, one after the other. We show that instances where relations are bijective functions yield precise and correct algorithm instances of our generalised union-find.
    [bibtex-key = fru_deriving_linear_algorithms_from_uf_chr06]
  440. Maurizio Gabbrielli, Maria Chiara Meo, and Paolo Tacchella. A compositional Semantics for CHR with propagation rules. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 93-107, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, semantics, CHR 2006, CHR 2006.
    Abstract:
    [bibtex-key = gabbrielli_meo_tacchella_compositional_semantics_chr06]
  441. Sandrine-Dominique Gouraud and Arnaud Gotlieb. Using CHRs to Generate Functional Test Cases for the Java Card Virtual Machine. In P. Van Hentenryck, editor, PADL '06: Proc. 8th Intl. Symp. Practical Aspects of Declarative Languages, volume 3819 of LNCS, pages 1-15, January 2006. SV. [doi:10.1007/11603023_1] Keyword(s): applications, testing. [bibtex-key = gouraud_gotlieb_javacard_padl06]
  442. Michael Hanus. Adding Constraint Handling Rules to Curry. In M. Fink, H. Tompits, and S. Woltran, editors, WLP '06: Proc. 20th Workshop on Logic Programming, T.U.Wien, Austria, INFSYS Research report 1843-06-02, pages 81-90, February 2006. Keyword(s): implementation. [bibtex-key = hanus_chr_curry_wlp06]
  443. Martin Kaeser and Marc Meister. Implementation of an F-Logic Kernel in CHR. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 33-47, July 2006. KULCW, Technical report CW 452. [PDF] Keyword(s): CHR 2006, CHR 2006, CHR 2006.
    Abstract:
    Constraint Handling Rules (CHR) is a concurrent, committed- choice, rule-based language, rewriting constraints in relational syntax. Frame-Logic is an extension of classical predicate logic which accounts in a declarative way for many features of object-orientation. This exploratory paper gives a concise CHR implementation of Frame-Logic's core features, including object-oriented constraint syntax, type-checking, and interaction of Frame-Logic deduction with non-monotonic overriding by inheritance.
    [bibtex-key = kaeser_meister_flogic_chr06]
  444. Nikolai Kosmatov. A constraint solver for sequences and its applications. In Proc. 2006 ACM Symp. on Applied Computing, pages 404-408, 2006. ACM. [bibtex-key = kosmatov_sequences_06]
  445. Nikolai Kosmatov. Constraint Solving for Sequences in Software Validation and Verification. In INAP '05: Proc. 16th Intl. Conf. Applications of Declarative Programming and Knowledge Management, volume 4369 of LNCS, pages 25-37, 2006. SV. [bibtex-key = kosmatov_sequences_inap05]
  446. Edmund S.L. Lam and Martin Sulzmann. Towards Agent Programming in CHR. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 17-31, July 2006. KULCW, Technical report CW 452. [PDF] Keyword(s): linear logic, CHR 2006, CHR 2006, CHR 2006.
    Abstract:
    We investigate an approach to the design and implementation of linear logic based agent systems via the linear logic semantics of Constraint Handling Rules (CHR). The intuition behind our approach is simple: Linear logic provides strong logical foundations to reason, verify and specify agent systems beyond the limitations of classical logics, while with CHR, one can implement and analyse agent systems in a concise and compact manner by executable inference rules. We discuss necessary refinements of the CHR semantics to allow for sequential computations of actions and the verification of action determinism. Our approach can possibly provide a seemless integration of the formal specification and implementation of agent programs via CHRs.
    [bibtex-key = lam_sulz_linear_logic_agents_chr06]
  447. Marc Meister. Fine-grained Parallel Implementation of the Preflow-Push Algorithm in CHR. In M. Fink, H. Tompits, and S. Woltran, editors, WLP '06: Proc. 20th Workshop on Logic Programming, T.U.Wien, Austria, INFSYS Research report 1843-06-02, pages 172-181, February 2006. Keyword(s): algorithms, parallelism. [bibtex-key = meister_preflow_push_wlp06]
  448. Marc Meister, Khalil Djelloul, and Thom Frühwirth. Complexity of a CHR Solver for Existentially Quantified Conjunctions of Equations over Trees. In F. Azevedo and others, editors, CSCLP '06: Proc. 11th Annual ERCIM Workshop on Constraint Solving and Constraint Programming, volume 4651 of LNCS, pages 139-153, June 2006. SV. ISBN: 978-3-540-73816-9. [doi:10.1007/978-3-540-73817-6_9] Keyword(s): complexity, algorithms. [bibtex-key = meister_djelloul_fru_compl_tree_equations_csclp06]
  449. Marc Meister and Thom Frühwirth. Complexity of the CHR Rational Tree Equation Solver. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 77-91, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, complexity, algorithms, CHR 2006, CHR 2006.
    Abstract:
    Constraint Handling Rules (CHR) is a concurrent, committed- choice, rule-based language. One of the first CHR programs is the classic constraint solver for syntactic equality of rational trees that performs unification. The worst-case time (and space) complexity of this short and elegant solver so far was an open problem and assumed to be polynomial. In this paper we show that under the standard operational semantics of CHR there exist particular computations with n occurrences of variables and function symbols that produce O(2n) constraints, thus leading to exponential time and space complexity. We also show that the standard implementation of the solver in CHR libraries for Prolog may not terminate due to the Prolog built-in order used in comparing terms. Complexity can be improved to be quadratic for any term order under both standard and refined CHR semantics without changing the equation solver, when equations are transformed into that normal form.
    [bibtex-key = meister_fru_compl_rational_tree_chr06]
  450. Jacques Robin and Jairson Vitorino. ORCAS: Towards a CHR-Based Model-Driven Framework of Reusable Reasoning Components. In M. Fink, H. Tompits, and S. Woltran, editors, WLP '06: Proc. 20th Workshop on Logic Programming, T.U.Wien, Austria, INFSYS Research report 1843-06-02, pages 192-199, February 2006. [bibtex-key = robin_vitorino_orcas_wlp06]
  451. Tom Schrijvers and Maurice Bruynooghe. Polymorphic algebraic data type reconstruction. In A. Bossi and M.J. Maher, editors, PPDP06l, pages 85-96, July 2006. ACM. ISBN: 1-59593-388-3. Keyword(s): type systems. [bibtex-key = schr_bruynooghe_polymorphic_type_reconstruction_ppdp06]
  452. Tom Schrijvers, Bart Demoen, Gregory J. Duck, Peter J. Stuckey, and Thom Frühwirth. Automatic implication checking for CHR constraints. In RULE '05: 6th Intl. Workshop on Rule-Based Programming, volume 147(1) of ENTCS, pages 93-111, January 2006. Elsevier. [bibtex-key = schr_demoen_duck_stuck_fru_implication_checking_entcs06]
  453. Tom Schrijvers, Neng-Fa Zhou, and Bart Demoen. Translating Constraint Handling Rules into Action Rules. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 141-155, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, implementation, related formalisms, CHR 2006, CHR 2006.
    Abstract:
    CHR is a popular high-level language for implementing constraint solvers and other general purpose applications. It has a well-established operational semantics and quite a number of different implementations, prominently in Prolog. However, there is still much room for exploring the compilation of CHR to Prolog. Nearly all implementations rely on attributed variables. In this paper, we explore a different implementation target for CHR: B-Prolog's Action Rules (ARs). As a rule-based language, it is a good match for particular aspects of CHR. However, the strict adherence to CHR's refined operational semantics poses some difficulty. We report on our work in progress: a novel compilation schema, required changes to the AR language and the preliminary benchmarks and experiences.
    [bibtex-key = schr_zhou_demoen_action_rules_chr06]
  454. Jon Sneyers, Tom Schrijvers, and Bart Demoen. Dijkstra's Algorithm with Fibonacci Heaps: An Executable Description in CHR. In M. Fink, H. Tompits, and S. Woltran, editors, WLP '06: Proc. 20th Workshop on Logic Programming, T.U.Wien, Austria, INFSYS Research report 1843-06-02, pages 182-191, February 2006. Keyword(s): algorithms. [bibtex-key = sney_schr_demoen_dijkstra_chr_wlp06]
  455. Jon Sneyers, Tom Schrijvers, and Bart Demoen. Memory reuse for CHR. In S. Etalle and M. Truszczynski, editors, ICLP06l, volume 4079 of LNCS, pages 72-86, August 2006. SV. [doi:10.1007/11799573_8] Keyword(s): implementation, optimizing compilation.
    Abstract:
    Two Constraint Handling Rules compiler optimizations that drastically reduce the memory footprint of CHR programs are introduced. The reduction is the result of reusing suspension terms, the internal CHR constraint representation, and avoiding the overhead of constraint removal followed by insertion. The optimizations are defined formally and their correctness is proved. Both optimizations were implemented in the K.U.Leuven CHR system. Significant memory savings and speedups were measured on classical and well-known benchmarks.
    [bibtex-key = sney_schr_demoen_memory_reuse_iclp06]
  456. Peter J. Stuckey, Martin Sulzmann, and Jeremy Wazny. Type Processing by Constraint Reasoning. In N. Kobayashi, editor, APLAS '06: Proc. 4th Asian Symp. on Programming Languages and Systems, volume 4279 of LNCS, pages 1-25, November 2006. SV. Note: Invited talk. ISBN: 3-540-48937-1. Keyword(s): type systems. [bibtex-key = stuck_sulz_wazny_type_processing_by_constraint_reasoning_aplas06]
  457. Martin Sulzmann, Tom Schrijvers, and Peter J. Stuckey. Principal Type Inference for GHC-Style Multi-parameter Type Classes. In N. Kobayashi, editor, APLAS '06: Proc. 4th Asian Symp. on Programming Languages and Systems, volume 4279 of LNCS, pages 26-43, November 2006. SV. ISBN: 3-540-48937-1. Keyword(s): type systems. [bibtex-key = sulz_schr_stuck_aplas06]
  458. Martin Sulzmann and Meng Wang. Modular generic programming with extensible superclasses. In Proceedings of the 2006 ACM SIGPLAN workshop on Generic programming, WGP '06, pages 55-65, 2006. ACM. ISBN: 1-59593-492-8. [WWW] Keyword(s): type systems. [bibtex-key = Sulzmann:2006:MGP:1159861.1159869]
  459. Martin Sulzmann, Jeremy Wazny, and Peter J. Stuckey. A Framework for Extended Algebraic Data Types. In FLOPS '06: Proc. 8th Intl. Symp. Functional and Logic Programming, volume 3945 of LNCS, pages 47-64, 2006. SV. [doi:10.1007/11737414_5] Keyword(s): type systems. [bibtex-key = sulzm_wazny_stuckey_eadt_flops06]
  460. Kazunori Ueda, Norio Kato, Koji Hara, and Ken Mizuno. LMNtal as a Unifying Declarative Language. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 1-15, July 2006. KULCW, Technical report CW 452. Note: Invited talk. [PDF] Keyword(s): related formalisms, CHR 2006, CHR 2006, CHR 2006.
    Abstract:
    LMNtal (pronounced "elemental") is a simple language model based on hierarchical graph rewriting that uses logical variables to represent connectivity and membranes to represent hierarchy. LMNtal is an outcome of the attempt to unify constraint-based concurrency and Constraint Handling Rules (CHR), the two notable extensions to concurrent logic programming. LMNtal is intended to be a substrate language of various computational models, especially those addressing concurrency, mobility and multiset rewriting. Another important goal of LMNtal has been to put hierarchical graph rewriting into practice and demonstrate its versatility by designing and implementing a full-fledged, monolithic programming language. In this paper, we demonstrate the practical aspects of LMNtal using a number of examples taken from diverse areas of computer science. Also, we discuss the relationship between LMNtal and CHR, which exhibit both commonalities and differences in various respects.
    [bibtex-key = ueda_LMNtal_chr06]
  461. Peter Van Weert, Jon Sneyers, Tom Schrijvers, and Bart Demoen. Extending CHR with Negation as Absence. In T. Schrijvers and Th. Frühwirth, editors, CHR06l, pages 125-140, July 2006. KULCW, Technical report CW 452. [POSTSCRIPT] Keyword(s): CHR 2006, extensions, CHR 2006, CHR 2006.
    Abstract:
    In this exploratory paper we introduce an extension of the CHR language with negation as absence, an established feature in production rule systems. Negation as absence is a procedural notion that allows a more concise and clean programming style. We propose a formal operational semantics close to CHR's refined operational semantics. We illustrate and motivate its properties with examples.
    [bibtex-key = vanweert_sney_schr_demoen_negation_chr06]
  462. Marco Alberti, Federico Chesani, Marco Gavanelli, and Evelina Lamma. The CHR-based Implementation of a System for Generation and Confirmation of Hypotheses. In A. Wolf, Th. Frühwirth, and M. Meister, editors, W(C)LP '05: Proc. 19th Workshop on (Constraint) Logic Programming, volume 2005-01 of UIB, pages 111-122, February 2005. [WWW] [bibtex-key = alberti_et_al_sys_gen_conf_hypoth_wclp05]
  463. Hariolf Betz and Thom Frühwirth. A Linear-Logic Semantics for Constraint Handling Rules. In CP05, volume 3709 of LNCS, pages 137-151, October 2005. SV. Keyword(s): semantics, linear logic. [bibtex-key = betz_fru_linear_logic_semantics_cp05]
  464. Henning Christiansen. Experiences and directions for Abduction and Induction using Constraint Handling Rules. In AIAI '05: Proc. Intl. Workshop on the Integration of Abduction and Induction in Artificial Intelligence, July 2005. Note: Position Paper. Keyword(s): abduction. [bibtex-key = christ_abduction_position_aiai05]
  465. Henning Christiansen. Reasoning about passive declarations in CHR. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 93-108, 2005. KULCW, Technical report CW 421. [POSTSCRIPT] Keyword(s): CHR 2005, optimizing compilation, CHR 2005, CHR 2005.
    Abstract:
    The programming language of Constraint Handling Rules (CHR) is gaining more and more popularity and this has motivated the development of new optimization techniques to be applied in implementations of CHR. As for other logic programming languages, a program written CHR can be understood declaratively as a logical formula and as a procedural specification, and CHR has different tools for manual optimization at the procedural level whose application may (or may not) sacrifice the declarative reading. One such optimization is given by passive declarations by means of which the search for rules to be applied can be optimized, perhaps changing which rules that are applied and in which order. A framework for analyzing the effect of passive declarations is presented in terms of a slightly abstract operational semantics which takes into account the effect of passive declarations. Based on it, we can give different classifications of the effect of some passive declarations that do not affect the logical semantics. This may be used for reasoning about manual optimizations as well as proposals for automatic strategies to be applied by a compiler for adding passive declarations.
    [bibtex-key = christ_passive_reasoning_chr05]
  466. Henning Christiansen and Verónica Dahl. HYPROLOG: A New Logic Programming Language with Assumptions and Abduction. In M. Gabbrielli and G. Gupta, editors, ICLP05l, volume 3668 of LNCS, pages 159-173, October 2005. SV. Keyword(s): abduction. [bibtex-key = christiansen_dahl_hyprolog_iclp05]
  467. Henning Christiansen and Verónica Dahl. Meaning in Context. In A. Dey, B. Kokinov, and R. Turner, editors, CONTEXT '05: Proc. 4th Intl. and Interdisciplinary Conf. Modeling and Using Context, volume 3554 of LNAI, pages 97-111, 2005. SV. [bibtex-key = christ_dahl_meaning_in_context_context05]
  468. Emmanuel Coquery and François Fages. A Type System for CHR. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 19-33, 2005. KULCW, Technical report CW 421. [PDF] Keyword(s): CHR 2005, type systems, CHR 2005, CHR 2005.
    Abstract:
    We propose a generic type system for the Constraint Handling Rules (CHR), a rewriting rule language for implementing constraint solvers. CHR being a high-level extension of a host language, such as Prolog or Java, this type system is parameterized by the type system of the host language. We show the consistency of the type system for CHR w.r.t. its operational semantics. We also study the case when the host language is a constraint logic programming language, typed with the prescriptive type system we developed in our previous work. In particular, we show the consistency of the resulting type system w.r.t. the extended execution model CLP+CHR. This system is implemented through an extension of our type checker TCLP for constraint logic languages. We report on experimental results about the type-checking of 12 CHR solvers and programs, including TCLP itself.
    [bibtex-key = coquery_fages_type_system_chr05]
  469. Verónica Dahl and Philippe Blache. Extracting Selected Phrases through Constraint Satisfaction. In Proc. 2nd Intl. Workshop on Constraint Solving and Language Processing, October 2005. [bibtex-key = dahl_blache_extracting_phrases_cslp05]
  470. Giorgio Delzanno, Maurizio Gabbrielli, and Maria Chiara Meo. A compositional semantics for CHR. In P. Barahona and A.P. Felty, editors, PPDP05l, pages 209-217, July 2005. ACM. ISBN: 1-59593-090-6. Keyword(s): semantics. [bibtex-key = delz_gab_meo_comp_sem_chr_ppdp05]
  471. Gregory J. Duck and Tom Schrijvers. Accurate Functional Dependency Analysis for Constraint Handling Rules. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 109-124, 2005. KULCW, Technical report CW 421. [POSTSCRIPT] Keyword(s): CHR 2005, implementation, optimizing compilation, CHR 2005, CHR 2005.
    Abstract:
    Information about functional dependencies is used by modern CHR compilers for both optimisation and for further program analysis (e.g. confluence analysis). Before this work, CHR compilers relied on an ad hoc analysis for functional dependencies based on searching for rules of a particular form and the results from late storage analysis. We present a more formal functional dependency analysis of CHRs based on abstract interpretation. We show, by example, that the new analysis is more accurate than the existing ad hoc analysis.
    [bibtex-key = duck_schr_accurate_funcdep_chr05]
  472. Thom Frühwirth. Logical Rules for a Lexicographic Order Constraint Solver. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 79-91, 2005. KULCW, Technical report CW 421. [POSTSCRIPT] Keyword(s): CHR 2005, CHR 2005, CHR 2005.
    Abstract:
    We give an executable specification of the global constraint of lexicographic order in Constraint Handling Rules (CHR) language. In contrast to previous approaches, the implementation is short and concise without giving up on linear time worst case time complexity. It is incremental and concurrent by nature of CHR. It is provably correct and confluent. It is independent of the underlying constraint system, and therefore not restricted to finite domains. We also show completeness of constraint propagation, i.e. that all possible consequences of the constraint are generated by the implementation. Our algorithm is encoded by three pairs of rules, two corresponding to base cases, two performing the obvious traversal of the sequences to be compared and two covering a not so obvious special case when the lexicographic constraint has a unique solution.
    [bibtex-key = fru_lexicographic_chr05]
  473. Thom Frühwirth. Parallelizing Union-Find in Constraint Handling Rules Using Confluence. In M. Gabbrielli and G. Gupta, editors, ICLP05l, volume 3668 of LNCS, pages 113-127, October 2005. SV. Keyword(s): confluence, algorithms, parallelism. [bibtex-key = fru_parallel_union_find_iclp05]
  474. Thom Frühwirth. Specialization of Concurrent Guarded Multi-Set Transformation Rules. In S. Etalle, editor, LOPSTR04, volume 3573 of LNCS, pages 133-148, 2005. SV. [PDF] [bibtex-key = fru_specialization_lopstr04]
  475. Luis Menezes, Jairson Vitorino, and Marcos Aurelio. A High Performance CHR${}^\lor$ Execution Engine. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 35-45, 2005. KULCW, Technical report CW 421. [PDF] Keyword(s): CHR 2005, implementation, disjunction, CHR 2005, CHR 2005.
    Abstract:
    Constraint Handling Rules with disjunction is a high-level language for writing constraint solvers either from scratch or by modifying existing solvers. In this work we present a proposal for a new rule execution strategy of CHR_ taking advantage of data structures more adequate to treat disjunctions within rules. We then compare this new approach with existing CHR_ implementations.
    [bibtex-key = menezes_vitorino_aurelio_high_performance_chr_or_chr05]
  476. Tom Schrijvers and Thom Frühwirth. Analysing the CHR Implementation of Union-Find. In A. Wolf, Th. Frühwirth, and M. Meister, editors, W(C)LP '05: Proc. 19th Workshop on (Constraint) Logic Programming, volume 2005-01 of UIB, pages 135-146, February 2005. [WWW] Keyword(s): algorithms, complexity. [bibtex-key = schr_fru_analysing_union_find_wclp05]
  477. Tom Schrijvers, Peter J. Stuckey, and Gregory J. Duck. Abstract interpretation for Constraint Handling Rules. In P. Barahona and A.P. Felty, editors, PPDP05l, pages 218-229, July 2005. ACM. ISBN: 1-59593-090-6. Keyword(s): optimizing compilation. [bibtex-key = schr_stuck_duck_ai_chr_ppdp05]
  478. Tom Schrijvers, Jan Wielemaker, and Bart Demoen. Poster: Constraint Handling Rules for SWI-Prolog. In A. Wolf, Th. Frühwirth, and M. Meister, editors, W(C)LP '05: Proc. 19th Workshop on (Constraint) Logic Programming, volume 2005-01 of UIB, February 2005. [WWW] [bibtex-key = schr_wielemaker_demoen_chr_swi_wclp05]
  479. Jon Sneyers, Tom Schrijvers, and Bart Demoen. Guard and Continuation Optimization for Occurrence Representations of CHR. In M. Gabbrielli and G. Gupta, editors, ICLP05l, volume 3668 of LNCS, pages 83-97, October 2005. SV. Keyword(s): implementation, optimizing compilation. [bibtex-key = sney_schr_demoen_guard_and_continuation_opt_iclp05]
  480. Jon Sneyers, Tom Schrijvers, and Bart Demoen. The Computational Power and Complexity of Constraint Handling Rules. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 3-17, 2005. KULCW, Technical report CW 421. [POSTSCRIPT] Keyword(s): CHR 2005, computability, complexity, CHR 2005, CHR 2005.
    Abstract:
    We introduce the CHR machine, a model of computation based on the Constraint Handling Rules programming language. Its computational power and time complexity properties are compared with those of the Turing machine and Random Access Memory machine. Our major result is the proof that every algorithm can be implemented in CHR with the best known time and space complexity.
    [bibtex-key = sney_schr_demoen_chr_complexity_chr05]
  481. Martin Sulzmann. Chameleon: Systematic Type System Design via Constraint Handling Rules. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 1, 2005. KULCW, Technical report CW 421. Note: Invited talk. Keyword(s): type systems, CHR 2005, CHR 2005. [bibtex-key = sulz_chameleon_chr05]
  482. Martin Sulzmann, Jeremy Wazny, and Peter J. Stuckey. Constraint Abduction and Constraint Handling Rules. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 63-78, 2005. KULCW, Technical report CW 421. [POSTSCRIPT] Keyword(s): CHR 2005, abduction, CHR 2005, CHR 2005.
    Abstract:
    Type inference for advanced type extensions demands constraints consisting of implications, universal quantifiers etc. Hence, the current CHR solving which rewrites sets of primitive constraints is not applicable. We define an extension of the CHR solving mechanism which incorporates abductive reasoning to solve implication constraints. We state some fundamental results such as soundness and under some sufficient conditions completeness and termination. We have implemented a prototype solver as part of the Chameleon system. Our results allows us to advance the state of art in constraint solving and achieve inference for expressive type extensions.
    [bibtex-key = sulz_wazny_stuck_abduction_chr05]
  483. Peter Thiemann. Grammar-based analysis of string expressions. In TLDI '05: Proc. 2005 ACM SIGPLAN Intl. workshop on Types in Languages Design and Implementation, New York, NY, USA, pages 59-70, 2005. ACM. ISBN: 1-58113-999-3. [doi:10.1145/1040294.1040300] [bibtex-key = thiemann_grammar_string_exprs_tldi05]
  484. Peter Van Weert, Tom Schrijvers, and Bart Demoen. K.U.Leuven JCHR: a user-friendly, flexible and efficient CHR system for Java. In T. Schrijvers and Th. Frühwirth, editors, CHR05l, pages 47-62, 2005. KULCW, Technical report CW 421. [WWW] [PDF] Keyword(s): CHR 2005, Java, implementation, CHR 2005, CHR 2005.
    Abstract:
    A new integration of Constraint Handling Rules (CHR) and Java is presented: the K.U.Leuven JCHR system. It was designed with three aims in mind: user-friendliness, exibility and efficiency. User-friendliness is achieved by providing a high-level syntax that feels familiar to both Java programmers and users of other CHR embeddings, and by full compliance to the refined operational semantics. Flexibility is the result of a well thought-out design, allowing e.g. an easy integration of built-in constraint solvers and variable types. Efficiency is achieved through an optimized compilation to Java and the use of a very efficient constraint store. The design of the K.U.Leuven JCHR system is presented, its implementation discussed and its performance is compared with other CHR systems embedded in Java and Prolog.
    [bibtex-key = vanweert_schr_demoen_jchr_chr05]
  485. Slim Abdennadher and Thom Frühwirth. Integration and Optimization of Rule-based Constraint Solvers. In M. Bruynooghe, editor, LOPSTR03, volume 3018 of LNCS, pages 198-213, 2004. SV. [PDF] [bibtex-key = abd_fru_integration_lopstr03]
  486. Dulce Aguilar-Solis and Verónica Dahl. Coordination Revisited -- A Constraint Handling Rule Approach. In IBERAMIA '04: Proc. 9th Ibero-American Conf. on AI, volume 3315 of LNCS, pages 315-324, November 2004. Keyword(s): applications. [bibtex-key = as_dahl_coordination_iberamia04]
  487. Marco Alberti, Davide Daolio, Paolo Torroni, Marco Gavanelli, Evelina Lamma, and Paola Mello. Specification and verification of agent interaction protocols in a logic-based system. In H. Haddad and others, editors, SAC '04: Proc. 19th ACM Symp. Applied Computing, pages 72-78, March 2004. ACM. Keyword(s): applications, verification. [bibtex-key = alberti_et_al_agent_interaction_protocols_sac04]
  488. Marco Alberti, Marco Gavanelli, Evelina Lamma, Paola Mello, and Paolo Torroni. Specification and Verification of Agent Interaction using Social Integrity Constraints. In LCMAS'03: Logic and Communication in Multi-Agent Systems, volume 85(2) of ENTCS, pages 94-116, 2004. Elsevier. [bibtex-key = alberti_et_al_social_integrity_constraints_lcmas03]
  489. Liviu Badea, Doina Tilivea, and Anca Hotaran. Semantic Web Reasoning for Ontology-Based Integration of Resources. In PPSWR '04: Proc. second Intl. Workshop on Principles And Practice Of Semantic Web Reasoning, volume 3208 of LNCS, pages 61-75, September 2004. SV. Keyword(s): applications. [bibtex-key = badea_et_al_semantic_web_reasoning_ppswr04]
  490. Henning Christiansen. CHR Grammars with multiple constraint stores. In Th. Frühwirth and M. Meister, editors, CHR04l, pages 1-7, May 2004. [PDF] Keyword(s): CHR 2004, linguistics, applications, CHR 2004, CHR 2004. [bibtex-key = christ_grammars_mult_stores_chr04]
  491. Verónica Dahl. An Abductive Treatment of Long Distance Dependencies in CHR. In CSLP '04: Proc. First Intl. Workshop on Constraint Solving and Language Processing, volume 3438 of LNCS, pages 17-31, 2004. SV. Note: Invited Paper. Keyword(s): abduction. [bibtex-key = dahl_abductive_dependencies_cslp04]
  492. Verónica Dahl and Kimberly Voll. Concept Formation Rules: An Executable Cognitive Model of Knowledge Construction. In NLUCS '04: Proc. First Intl. Workshop on Natural Language Understanding and Cognitive Sciences, April 2004. [bibtex-key = dahl_voll_concept_formation_rules_nlucs04]
  493. Gregory J. Duck, Simon Peyton-Jones, Peter J. Stuckey, and Martin Sulzmann. Sound and Decidable Type Inference for Functional Dependencies. In D. A. Schmidt, editor, ESOP '04: Proc. 13th European Symp. on Programming, volume 2986 of LNCS, pages 49-63, mar/apr 2004. SV. Keyword(s): type systems. [bibtex-key = duck_peyton_stuck_sulz_sound_decidable_type_inference_fd_esop04]
  494. Gregory J. Duck, Peter J. Stuckey, and Marìa Garcìa de la Banda. Compiling Ask Constraints. In B. Demoen and V. Lifschitz, editors, ICLP04l, volume 3132 of LNCS, pages 105-119, September 2004. SV. ISBN: 978-3-540-22671-0. [doi:10.1007/b99475] Keyword(s): implementation. [bibtex-key = duck_stuck_garc_compiling_ask_constraints_iclp04]
  495. Gregory J. Duck, Peter J. Stuckey, Marìa Garcìa de la Banda, and Christian Holzbaur. The Refined Operational Semantics of Constraint Handling Rules. In B. Demoen and V. Lifschitz, editors, ICLP04l, volume 3132 of LNCS, pages 90-104, September 2004. SV. ISBN: 978-3-540-22671-0. [doi:10.1007/b99475] Keyword(s): semantics, implementation. [bibtex-key = duck_stuck_garc_holz_refined_op_sem_iclp04]
  496. Gerald Penn and Frank Richter. Lexical Resource Semantics: From Theory to Implementation. In Stefan Mueller, editor, Proceedings of the 11th International Conference on Head-Driven Phrase Structure Grammar, pages 423-443, 2004. CSLI Publications. [bibtex-key = penn_richter_lexical_04]
  497. Tom Schrijvers. JmmSolve: A Generative Java Memory Model Implemented in Prolog and CHR. In B. Demoen and V. Lifschitz, editors, ICLP04l, volume 3132 of LNCS, pages 475-476, September 2004. SV. ISBN: 978-3-540-22671-0. [doi:10.1007/b99475] Keyword(s): applications. [bibtex-key = schr_JmmSolve_iclp04]
  498. Tom Schrijvers and Bart Demoen. The K.U.Leuven CHR system: Implementation and application. In Th. Frühwirth and M. Meister, editors, CHR04l, pages 8-12, May 2004. [WWW] [POSTSCRIPT] Keyword(s): CHR 2004, implementation, CHR 2004, CHR 2004.
    Abstract:
    We present the K.U.Leuven CHR system: what started out as a validation of a new attributed variables implementation, has become part of three different Prolog systems with an increasing userbase. In this paper we highlight the particular implementation aspects of the K.U.Leuven CHR system, and a few CHR applications that we have built with our system.
    [bibtex-key = schr_demoen_kulchr_chr04]
  499. Tom Schrijvers and David S. Warren. Constraint Handling Rules and tabled execution. In B. Demoen and V. Lifschitz, editors, ICLP04l, volume 3132 of LNCS, pages 120-136, September 2004. SV. ISBN: 978-3-540-22671-0. [doi:10.1007/b99475] Keyword(s): implementation. [bibtex-key = schr_warren_chr_xsb_iclp04]
  500. Hugo Simões and Mário Florido. TypeTool: A Type Inference Visualization Tool. In H. Kuchen, editor, WFLP '04: Proc. 13th Intl. Workshop on Functional and (Constraint) Logic Programming, RWTH Aachen, deptcw, Technical report AIB-2004-05, Aachen, Germany, pages 48-61, June 2004. Keyword(s): type systems. [bibtex-key = simoes_florido_typetool_wflp04]
  501. Peter J. Stuckey, Martin Sulzmann, and Jeremy Wazny. The Chameleon System. In Th. Frühwirth and M. Meister, editors, CHR04l, pages 13-32, May 2004. [WWW] [POSTSCRIPT] Keyword(s): CHR 2004, type systems, CHR 2004, CHR 2004.
    Abstract:
    We give an overview of the major features of the Chameleon programming language, as well as use of the system, from a Haskell programmer's point of view. Chameleon supports type-class overloading a la Haskell. The novelty of Chameleon is to allow the programmer to specify almost arbitrary conditions on type classes in terms of Constraint Handling Rules (CHRs). In fact, Chameleon's entire type inference system and evidence translation of programs is phrased in terms of CHRs.
    [bibtex-key = stuck_sulz_wazny_chameleon_chr04]
  502. Sebastian Brand and Eric Monfroy. Deductive Generation of Constraint Propagation Rules. In G. Vidal, editor, RULE '03: 4th Intl. Workshop on Rule-Based Programming, volume 86(2) of ENTCS, pages 45-60, September 2003. Elsevier. Keyword(s): program generation. [bibtex-key = brand_monfroy_generation_propagation_rules_entcs03]
  503. Gabriel G. Bès and Verónica Dahl. Balanced parentheses in NL texts: a useful cue in the syntax/semantics interface. In Proc. Lorraine-Saarland Workshop on Prospects and Advances in the Syntax/Semantics Interface, October 2003. Note: Poster Paper. Keyword(s): applications, linguistics. [bibtex-key = bes_dahl_balanced_2003]
  504. Emmanuel Coquery and François Fages. TCLP: A type checker for CLP($\mathcal{X}$). In F. Mesnard and A. Serebrenik, editors, WLPE03, KULCW, Technical report CW 371, pages 17-30, 2003. Keyword(s): type systems. [bibtex-key = coquery_fages_type_system_wlpe03]
  505. Gregory J. Duck, Peter J. Stuckey, Marìa Garcìa de la Banda, and Christian Holzbaur. Extending arbitrary solvers with Constraint Handling Rules. In PPDP03, pages 79-90, 2003. ACM. ISBN: 1-58113-705-2. Keyword(s): implementation. [bibtex-key = duck_stuck_garcia_holz_extending_arbitrary_solvers_with_chr_ppdp03]
  506. Thom Frühwirth and Christian Holzbaur. Source-to-Source Transformation for a Class of Expressive Rules. In F. Buccafurri, editor, AGP '03: Joint Conf. Declarative Programming APPIA-GULP-PRODE, pages 386-397, September 2003. [bibtex-key = fru_holz_source2source_agp03]
  507. Marco Gavanelli, Evelina Lamma, Paola Mello, Michela Milano, and Paolo Torroni. Interpreting Abduction in CLP. In F. Buccafurri, editor, AGP '03: Joint Conf. Declarative Programming APPIA-GULP-PRODE, pages 25-35, September 2003. Keyword(s): abduction. [bibtex-key = gavanelli_et_al_interpreting_abduction_agp03]
  508. Eric Monfroy and Carlos Castro. Basic components for constraint solver cooperations. In SAC '03: Proc. 2003 ACM symposium on Applied Computing, New York, NY, USA, pages 367-374, 2003. ACM. ISBN: 1-58113-624-2. [doi:10.1145/952532.952606] [bibtex-key = monfroy_castro_coorporations_sac03]
  509. Gerald Penn and Mohammad Haji-Abdolhosseini. Topological parsing. In EACL '03: Proc. of the 10th conf. of the European chapter of the Assoc. for Computational Linguistics, Morristown, NJ, USA, pages 283-290, 2003. Association for Computational Linguistics. ISBN: 1-333-56789-0. [doi:10.3115/1067807.1067845] [bibtex-key = penn_ha_top_parsing_eacl03]
  510. Tom Schrijvers, David S. Warren, and Bart Demoen. CHR for XSB. In R. Lopes and M. Ferreira, editors, CICLOPS '03: Proc. 3rd Intl. Colloq. on Implementation of Constraint and Logic Programming Systems, University of Porto, Portugal, deptcw, Technical report DCC-2003-05, pages 7-20, December 2003. Keyword(s): implementation. [bibtex-key = schr_warren_demoen_chr_xsb_ciclops03]
  511. Slim Abdennadher, Ekkerhard Krämer, Matthias Saft, and Matthias Schmauss. JACK: A Java Constraint Kit. In M. Hanus, editor, WFLP '01: Proc. 10th Intl. Workshop on Functional and (Constraint) Logic Programming, Selected Papers, volume 64 of ENTCS, pages 1-17, November 2002. Elsevier. Note: See also http://pms.ifi.lmu.de/software/jack/. Keyword(s): Java. [bibtex-key = abd_kr_saft_schm_jack_wflp01:entcs02]
  512. Sandra Alves and Mario Florido. Type Inference using Constraint Handling Rules. In M. Hanus, editor, WFLP '01: Proc. 10th Intl. Workshop on Functional and (Constraint) Logic Programming, Selected Papers, volume 64 of ENTCS, pages 56-72, November 2002. Elsevier. Keyword(s): type systems. [bibtex-key = alves_florido_type_inference_chr_wflp01:entcs02]
  513. Liviu Badea and Doina Tilivea. Intelligent Information Integration as a Constraint Handling Problem. In FQAS '02: Proc. 5th Intl. Conf. on Flexible Query Answer Systems, volume 2522 of LNCS, October 2002. SV. [doi:10.1007/3-540-36109-X_2]
    Abstract:
    Intelligent Information Integration (I3) aims at combining heterogeneous and distributed information sources by explicitly representing and reasoning about their content, giving the user the illusion of interacting with a uniform system. In this paper we show how query planning in such a system can be reduced to a constraint handling problem. Conceptually, our approach relies on a generalized abductive reasoning mechanism involving so called partially open predicates, which support a seamless combination of backward (goal-directed) and forward reasoning. The original aspects of our approach consist in the early detection of (plan) inconsistencies using forward propagation of constraints as well as in the seamless interleaving of query planning and execution. Unlike other specialized query planning algorithms, for which domain reasoning and query planning are only loosely coupled, our encoding of source and domain models into Constraint Handling Rules allows us to fully and efficiently exploit existing domain knowledge. The ability to automatically derive source interactions from domain models (ontologies) enhances the flexibility of modeling.
    [bibtex-key = bedea_tilivea_iii_fqas02]
  514. Sebastian Brand. A Note on Redundant Rules in Rule-based Constraint Programming. In Joint ERCIM/CologNet Intl. Workshop on Constraint Solving and Constraint Logic Programming, Selected papers, volume 2627 of LNCS, pages 279-336, June 2002. SV. Keyword(s): optimizing compilation. [bibtex-key = brand_redundant_rules_csclp02]
  515. Aykut Firat, Stuart Madnick, and Benjamin Grosof. Financial information integration in the presence of equational ontological conflicts. In Proc. 12th Workshop Information Technologies and Systems, 2002.
    Abstract:
    While there are efforts to establish a single international accounting standard, there are strong current and future needs to handle heterogeneous accounting methods and systems. We advocate a context-based approach to dealing with multiple accounting standards and equational ontological conflicts. In this paper we first define what we mean by equational ontological conflicts and then describe a new approach, using Constraint Logic Programming and abductive reasoning, to reconcile such conflicts among disparate information systems. In particular, we focus on the use of Constraint Handling Rules as a simultaneous symbolic equation solver, which is a powerful way to combine, invert and simplify multiple conversion functions that translate between different contexts. Finally, we demonstrate a sample application using our prototype implementation that demonstrates the viability of our approach.
    [bibtex-key = financ_info_integration_wits02]
  516. Thom Frühwirth. As Time Goes By II: More Automatic Complexity Analysis of Concurrent Rule Programs. In A. Di Pierro and H. Wiklicky, editors, QAPL '01: Proc. First Intl. Workshop on Quantitative Aspects of Programming Languages, volume 59(3) of ENTCS, 2002. Elsevier. Keyword(s): complexity. [bibtex-key = fru_complexity2_entcs02]
  517. Thom Frühwirth. As Time Goes By: Automatic Complexity Analysis of Simplification Rules. In D. Fensel, F. Giunchiglia, D. McGuinness, and M.-A. Williams, editors, KR '02: Proc. 8th Intl. Conf. Princ. Knowledge Representation and Reasoning, pages 547-557, April 2002. MK. Keyword(s): complexity. [bibtex-key = fru_complexity_kr02]
  518. Thom Frühwirth, Alessandra Di Pierro, and Herbert Wiklicky. Probabilistic Constraint Handling Rules. In M. Comini and M. Falaschi, editors, WFLP '02: Proc. 11th Intl. Workshop on Functional and (Constraint) Logic Programming, Selected Papers, volume 76 of ENTCS, June 2002. Elsevier. Keyword(s): probabilistic CHR, extensions. [bibtex-key = fru_dipierro_wiklicky_probabilistic_chr_wflp02]
  519. Harald Ganzinger and David A. McAllester. Logical Algorithms. In P. J. Stuckey, editor, ICLP02l, volume 2401 of LNCS, pages 209-223, jul/aug 2002. SV. Keyword(s): related formalisms. [bibtex-key = ganzinger_mcallester_la_iclp02]
  520. Diego Garat and Dina Wonsever. A Constraint Parser for Contextual Rules. In Proc. 22nd Intl. Conf. of the Chilean Computer Science Society, pages 234-242, November 2002. IEEE Computer Society. [bibtex-key = garat_wonsever_parser_contextual_rules_sccc02]
  521. Michael J. Maher. Propagation completeness of reactive constraints. In P. J. Stuckey, editor, ICLP02l, volume 2401 of LNCS, pages 148-162, jul/aug 2002. SV. [bibtex-key = propagation_completeness_maher_iclp02]
  522. Eduardo Torres Schumann. A Literate Programming System for Logic Programs with Constraints. In M. Comini and M. Falaschi, editors, WFLP '02: Proc. 11th Intl. Workshop on Functional and (Constraint) Logic Programming, University of Udine, Research Report UDMI/18/2002/RR, 2002. [bibtex-key = torres_literate_programming_wflp02]
  523. Christian Seitz, Bernhard Bauer, and Michael Berger. Planning and Scheduling in Multi Agent Systems using Constraint Handling Rules. In IC-AI '02: Proc. Intl. Conf. Artificial Intelligence, June 2002. CSREA Press. [bibtex-key = seitz_bauer_berger_MAS_icai02]
  524. Michael Thielscher. Reasoning About Actions with CHRs and Finite Domain Constraints. In P. J. Stuckey, editor, ICLP02l, volume 2401 of LNCS, pages 70-84, jul/aug 2002. SV. [bibtex-key = thielscher_actions_iclp02]
  525. Slim Abdennadher and Christophe Rigotti. Using confluence to generate rule-based constraint solvers. In R. De Nicola and H. Sondergaard, editors, PPDP01l, pages 127-135, September 2001. ACM. ISBN: 1-58113-388-X. Keyword(s): confluence. [bibtex-key = abd_rigotti_solver_generation_confluence_ppdp01]
  526. Slim Abdennadher and Matthias Saft. A visualization tool for Constraint Handling Rules. In A. Kusalik, editor, WLPE01, December 2001. [bibtex-key = abd_saft_jack:visualchr_wlpe01]
  527. Thom Frühwirth. On the Number of Rule Applications in Constraint Programs. In A. Dovier, M. Chiara Meo, and A. Omicini, editors, Declarative Programming - Selected Papers from AGP 2000, volume 48 of ENTCS, pages 147-166, June 2001. Elsevier. Keyword(s): complexity, termination. [bibtex-key = fru_number_entcs01]
  528. Joost Geurts, Jacco van Ossenbruggen, and Lynda Hardman. Application-Specific Constraints for Multimedia Presentation Generation. In MMM '01: Proc. 8th Intl. Conf. on Multimedia Modeling, pages 247-266, November 2001. Keyword(s): applications. [bibtex-key = geurts_vanOss_hardman_multimedia_presentation_cuypers_mm01]
  529. Armin Wolf. Adaptive Constraint Handling with CHR in Java. In T. Walsh, editor, CP01, volume 2239 of LNCS, pages 256-270, 2001. SV. ISBN: 3-540-42863-1. Keyword(s): Java, extensions. [bibtex-key = wolf_adaptive_chr_java_cp01]
  530. Armin Wolf. Attributed Variables for Dynamic Constraint Solving. In Proc. 14th Intl. Conf. Applications of Prolog, pages 211-219, October 2001. Prolog Association of Japan. Keyword(s): implementation, extensions. [bibtex-key = wolf_attr_vars_inap01]
  531. Slim Abdennadher. A Language for Experimenting with Declarative Paradigms. In T. Frühwirth and others, editors, RCoRP '00(bis): Proc. 2nd Workshop on Rule-Based Constraint Reasoning and Programming, September 2000. Keyword(s): disjunction. [bibtex-key = abd_chr_disjunction_rcorp00]
  532. Slim Abdennadher and Henning Christiansen. An Experimental CLP Platform for Integrity Constraints and Abduction. In FQAS '00: Proc. 4th Intl. Conf. Flexible Query Answering Systems, pages 141-152, October 2000. SV. Keyword(s): abduction. [bibtex-key = abd_christ_abduction_fqas00]
  533. Slim Abdennadher, Matthias Saft, and Sebastian Will. Classroom Assignment using Constraint Logic Programming. In PACLP '00: Proc. 2nd Intl. Conf. and Exhibition on Practical Application of Constraint Technologies and Logic Programming, April 2000. [bibtex-key = abd_saft_will_classroom_assignment_paclp00]
  534. Thom Frühwirth. Proving Termination of Constraint Solver Programs. In K.R. Apt, A.C. Kakas, E. Monfroy, and F. Rossi, editors, New Trends in Constraints, Joint ERCIM/Compulog Net Workshop, October 1999, Selected papers, volume 1865 of LNCS, pages 298-317, 2000. SV. ISBN: 3-540-67885-9. [doi:10.1007/3-540-44654-0_15] Keyword(s): termination. [bibtex-key = fru_termination_compulog00]
  535. Heiko Lötzbeyer and Alexander Pretschner. AutoFocus on Constraint Logic Programming. In LPSE '00: Proc. Intl. Workshop on (Constraint) Logic Programming and Software Engineering, July 2000. [bibtex-key = lotzbeyer_pretschner_autofocus_lpse00]
  536. Frank Morawietz. Chart Parsing and Constraint Programming. In M. Kay, editor, COLING '00: Proc. 18th Intl. Conf. on Computational Linguistics, jul/aug 2000. MK. [bibtex-key = morawietz_chart_parsing_coling00]
  537. Gerald Penn. Applying Constraint Handling Rules to HPSG. In T. Frühwirth and others, editors, RCoRP '00: Proc. 1st Workshop on Rule-Based Constraint Reasoning and Programming, July 2000. [bibtex-key = penn_hpsg_rcorp00]
  538. Carlos Ribeiro, André Zúquete, Paulo Ferreira, and Paulo Guedes. Security policy consistency. In T. Frühwirth and others, editors, RCoRP '00: Proc. 1st Workshop on Rule-Based Constraint Reasoning and Programming, July 2000. [bibtex-key = ribeiro_et_al_security_policy_consistency_rcorp00]
  539. Georg Ringwelski and Hans Schlenker. Type Inference in CHR Programs for the Composition of Constraint Systems. In S. Abdennadher, U. Geske, and D. Seipel, editors, WLP '00: Proc. 15th Workshop on Logic Programming, pages 137-146, August 2000. Keyword(s): type systems. [bibtex-key = ring_schlenk_inference_wlp00]
  540. Georg Ringwelski and Hans Schlenker. Using typed interfaces to compose CHR programs. In T. Frühwirth and others, editors, RCoRP '00(bis): Proc. 2nd Workshop on Rule-Based Constraint Reasoning and Programming, September 2000. [bibtex-key = ring_schlenk_interfaces_rcorp00bis]
  541. Armin Wolf. Projection in Adaptive Constraint Handling. In K.R. Apt, A.C. Kakas, E. Monfroy, and F. Rossi, editors, New Trends in Constraints, Joint ERCIM/Compulog Net Workshop, October 1999, Selected papers, volume 1865 of LNCS, pages 318-338, 2000. SV. ISBN: 3-540-67885-9. [bibtex-key = wolf_projection_compulog00]
  542. Armin Wolf. Toward a Rule-Based Solution of Dynamic Constraint Hierarchies Over Finite Domains. In T. Frühwirth and others, editors, RCoRP '00: Proc. 1st Workshop on Rule-Based Constraint Reasoning and Programming, July 2000. [bibtex-key = wolf_rule_based_hierarchies_rcorp00]
  543. Slim Abdennadher and Thom Frühwirth. Operational Equivalence of CHR Programs and Constraints. In J. Jaffar, editor, CP99l, volume 1713 of LNCS, pages 43-57, October 1999. SV. ISBN: 3-540-66626-5. Keyword(s): semantics. [bibtex-key = abd_fru_equivalence_cp99]
  544. Christian Holzbaur and Thom Frühwirth. Compiling Constraint Handling Rules into Prolog with Attributed Variables. In G. Nadathur, editor, PPDP99, volume 1702 of LNCS, pages 117-133, 1999. SV. Keyword(s): implementation. [bibtex-key = holz_fru_compiling_chr_attr_vars_ppdp99]
  545. Carlos Ribeiro and Paulo Guedes. Verifying workflow processes against organization security policies. In WETICE '99: Proc. 8th Workshop on Enabling Technologies on Infrastructure for Collaborative Enterprises, 1999. IEEE Computer Society. [doi:10.1109/ENABL.1999.805198] [bibtex-key = ribeiro_guedes_wetice99]
  546. Slim Abdennadher and Thom Frühwirth. On Completion of Constraint Handling Rules. In M. J. Maher and J.-F. Puget, editors, CP98l, volume 1520 of LNCS, pages 25-39, October 1998. SV. ISBN: 3-540-65224-8. Keyword(s): program generation. [bibtex-key = abd_fru_completion_cp98]
  547. Slim Abdennadher and Heribert Schütz. CHR$^\vee$, A Flexible Query Language. In T. Andreasen, H. Christiansen, and H.L. Larsen, editors, FQAS '98: Proc. 3rd Intl. Conf. on Flexible Query Answering Systems, volume 1495 of LNAI, pages 1-14, May 1998. SV. Keyword(s): disjunction. [bibtex-key = abd_query_lang_fqas98]
  548. Stéphane Bressan and Cheng Hian Goh. Answering Queries in Context. In T. Andreasen, H. Christiansen, and H.L. Larsen, editors, FQAS '98: Proc. 3rd Intl. Conf. on Flexible Query Answering Systems, volume 1495 of LNAI, pages 68-82, May 1998. SV. [bibtex-key = bressan_goh_coin_fqas98]
  549. Thom Frühwirth and Pascal Brisset. Optimal Placement of Base Stations in Wireless Indoor Telecommunication. In M. J. Maher and J.-F. Puget, editors, CP98l, volume 1520 of LNCS, pages 476-480, October 1998. SV. ISBN: 3-540-65224-8. Keyword(s): applications. [bibtex-key = fru_brisset_wireless_cp98]
  550. Slim Abdennadher. Operational Semantics and Confluence of Constraint Propagation Rules. In G. Smolka, editor, CP '97: Proc. Third Intl. Conf. Principles and Practice of Constraint Programming, volume 1330 of LNCS, pages 252-266, 1997. SV. Keyword(s): confluence, semantics. [bibtex-key = abd_sem_conf_prop_rules_cp97]
  551. Stéphane Bressan. Overview of a Prolog implementation of COntext INterchange mediator. In PAP '97: Proc. Fifth Intl. Conf. Pract. Applic. Prolog, London, 1997. Practical Application Company Ltd.. [bibtex-key = bressan_coin_pap97]
  552. Stéphane Bressan, Cheng Hian Goh, Thomas Lee, Stuart Madnick, and Michael Siege. A Procedure for Mediation of Queries to Sources in Disparate Contexts. In Proc. Intl. Logic Programming Symp., pages 213-228, 1997. MIT Press.
    Abstract:
    This paper discusses the algorithm we are using for the mediation of queries to disparate information sources in a Context Interchange system, where information sources may have different interpretations arising from their respective context. Queries are assumed to be formulated without regard for semantic heterogeneity, and are rewritten to corresponding mediated queries by taking into account the semantics of data codified in axioms associated with sources and receivers (the corresponding context theories). Our approach draws upon recent advances in abductive logic programming and presents an integration of techniques for query rewriting and semantic query optimization. We also demonstrate how this can be efficiently implemented using the constraint logic programming system ECLiPSe.
    [bibtex-key = bressan_et_al_mediation_lp97]
  553. Slim Abdennadher, Thom Frühwirth, and Holger Meuss. On confluence of Constraint Handling Rules. In CP '96: Proc. Second Intl. Conf. Principles and Practice of Constraint Programming, volume 1118 of LNCS, pages 1-15, August 1996. SV. [doi:10.1007/3-540-61551-2_62] Keyword(s): confluence.
    Abstract:
    We introduce the notion of confluence for Constraint Handling Rules (CHR), a powerful language for writing constraint solvers. With CHR one simplifies and solves constraints by applying rules. Confluence guarantees that a CHR program will always compute the same result for a given set of constraints independent of which rules are applied. We give a decidable, sufficient and necessary syntactic condition for confluence. Confluence turns out to be an essential syntactical property of CHR programs for two reasons. First, confluence implies correctness (as will be shown in this paper). In a correct CHR program, application of CHR rules preserves logical equivalence of the simplified constraints. Secondly, even when the program is already correct, confluence is highly desirable. Otherwise, given some constraints, one computation may detect their inconsistency while another one may just simplify them into a still complex constraint. As a side-effect, the paper also gives soundness and completeness results for CHR programs. Due to their special nature, and in particular correctness, these theorems are stronger than what holds for the related families of (concurrent) constraint programming languages.
    [bibtex-key = abd_fru_meuss_on_confluence_cp96]
  554. Marìa Teresa Escrig Monferrer and Francisco Toledo Lobo. Enhancing qualitative relative orientation with qualitative distance for robot path planning. In ICTAI '96: Proc. 8th IEEE Intl. Conf. Tools with Artif. Intell., pages 174-182, November 1996. IEEE Computer Society. [doi:10.1109/TAI.1996.560449] [bibtex-key = escrig_toledo_ictai96]
  555. Eric Monfroy, Michael Rusinowitch, and René Schott. Implementing non-linear constraints with cooperative solvers. In SAC '96: Proc. 1996 ACM symposium on Applied Computing, pages 63-72, 1996. ACM Press. ISBN: 0-89791-820-7. [doi:10.1145/331119.331147] [bibtex-key = monfroy_et_al_nonlinear_cooperative_sac96]
  556. Thom Frühwirth. Constraint Handling Rules. In A. Podelski, editor, Constraint Programming: Basic and Trends --- Selected Papers of the 22nd Spring School in Theoretical Computer Sciences, May 16--20, 1994, volume 910 of LNCS, pages 90-107, 1995. SV. ISBN: 3-540-59155-9. Keyword(s): tutorial. [bibtex-key = fru_chr_cp95]
  557. Thom Frühwirth. Entailment simplification and constraint constructors for user-defined constraints. In WCLP '93: 3rd Workshop on Constraint Logic Programming, March 1993. [bibtex-key = fru_entailment_wclp93]
  558. Iliano Cervesato and Edmund S.L. Lam. Concurrent Logic Programming: Met and Unmet Promises. Technical report, 2016. [PDF] [bibtex-key = cervesatoconcurrent]
  559. Alejandro Serrano and Jurriaan Hage. Context-Dependent Type Error Diagnosis for Functional Languages. Technical report, Department of Information and Computing Sciences, Utrecht University, Utrecht, The Netherlands, 2016. ISSN: 0924-3275. [PDF] [bibtex-key = serrano2016context]
  560. Alejandro Serrano and Jurriaan Hage. From Attribute Grammars to Constraint Handling Rules. Technical report, Department of Information and Computing Sciences, Utrecht University, Utrecht, The Netherlands, 2016. ISSN: 0924-3275. [PDF] [bibtex-key = serrano2016attribute]
  561. Hariolf Betz, Frank Raiser, and Thom Frühwirth. A complete and terminating execution model for Constraint Handling Rules. Ulmer Informatik Berichte 2010-01, Ulm University, Germany, January 2010. [WWW] Keyword(s): semantics, termination.
    Abstract:
    We observe that the various formulations of the operational semantics of Constraint Handling Rules proposed over the years fall into a spectrum ranging from the analytical to the pragmatic. While existing analytical formulations facilitate program analysis and formal proofs of program properties, they cannot be implemented as is. We propose a novel operational semantics, which has a strong analytical foundation, while featuring a terminating execution model. We prove its soundness and completeness with respect to existing analytical formulations and we compare its expressivity to that of various other formulations.
    [bibtex-key = betz_raiser_fru_execution_model_report10]
  562. Pierre Deransart and Rafael Oliveira. Towards a Generic Framework to Generate Explanatory Traces of Constraint Solving and Rule-Based Reasoning. Technical report 7165, INRIA, Paris -- Rocquenfourt, December 2010. [WWW] Keyword(s): applications.
    Abstract:
    In this report, we show how to use the Simple Fluent Calculus (SFC) to specify generic tracers, i.e. tracers which produce a generic trace. A generic trace is a trace which can be produced by different implementations of a software component and used independently from the traced component. This approach is used to define a method for extending a Java based \CHRor\ platform called CHROME (Constraint Handling Rule Online Model-driven Engine) with an extensible generic tracer. The method includes a tracer specification in SFC, a methodology to extend it, and the way to integrate it with CHROME, resulting in the platform CHROME-REF (for Reasoning Explanation Facilities), which is a constraint solving and rule based reasoning engine with explanatory traces.
    [bibtex-key = deransart_oliveira_generic_traces_techrep10]
  563. Paolo Pilozzi and Danny De Schreye. Scaling termination proofs by a characterization of cycles in CHR. Technical report CW 541, KULCW, Leuven, Belgium, April 2009. [WWW] Keyword(s): termination .
    Abstract:
    In the current paper, we discuss cycles in Constraint Handling Rules for the purpose of scaling termination proofs. In order to obtain a useful characterization, our approach differs from the ones used in other declarative languages, such as Logic Programming and Term Rewrite Systems. Due to multi-headed rules, the notion of a cycle is not in direct correspondence with the recursive calls of a program. Our characterization has to be more refined as we have to consider also partner constraints. Furthermore, a second, more challenging problem, due to the multi-set semantics of CHR, makes it unclear how cycles structurally compose. To tackle this problem, we develop a new abstraction for computations in CHR based on hypergraphs. On the basis of this abstraction, we define CHR constructs as a representation for sub-computations. These constructs introduce a concept of minimality and structural composability, making it is a useful abstraction. On the basis of this abstraction we define the meaning of a CHR cycle. These are special kinds of CHR constructs. We have developed a verification for detecting whether constructs are CHR cycles and for deriving the minimal CHR cycles of a program. We motivate why and how this will lead to scalable automated termination proof procedures for CHR.
    [bibtex-key = pilozzi_deschr_scaling_termination_techrep09]
  564. Frank Raiser. Semi-automatic generation of CHR solvers from global constraint automata. Ulmer Informatik Berichte 2008-03, Ulm University, Germany, February 2008. [WWW] Keyword(s): program generation. [bibtex-key = raiser_globalconstraintautomata_techrep08]
  565. Peter Van Weert. Compiling Constraint Handling Rules to Java: A Reconstruction. Technical report CW 521, KULCW, Leuven, Belgium, August 2008. [WWW] Keyword(s): Java.
    Abstract:
    In this report, we provide a detailed description of the compilation scheme the K.U.Leuven JCHR system uses to compile CHR to efficient Java code. We start from a relatively straightforward adaptation of the traditional CHR compilation scheme for Prolog, and gradually add all its basic optimizations. Next, we show why this compilation scheme is not suited for compilation to an imperative host language such as Java. We therefore introduce a novel compilation scheme from CHR to Java that uses explicit call stack maintenance and trampoline-style compilation to guarantee that executing recursive CHR programs no longer results in call stack overflows. The empirical evaluation of the improved compilation scheme confirms it is mostly superior to the traditional one.
    [bibtex-key = vanweert_jchr_compilation_techrep08]
  566. Peter Van Weert. Optimization of CHR Propagation Rules: Extended report. Technical report CW 519, KULCW, Leuven, Belgium, August 2008. [WWW] Keyword(s): implementation, optimizing compilation.
    Abstract:
    Constraint Handling Rules (CHR) is an elegant, high-level programming language based on multi-headed, forward chaining rules. To ensure CHR propagation rules are applied at most once with the same combination of constraints, CHR implementations maintain a so-called propagation history. The performance impact of this history can be significant. We introduce several optimizations that, for the majority of CHR rules, eliminate this overhead. We formally prove their correctness, and evaluate their implementation in two state-of-the-art CHR systems. This extended report contains complete formal proofs of all theoretical results.
    [bibtex-key = vanweert_histories_techrep08]
  567. Dean Voets, Paolo Pilozzi, and Danny De Schreye. A new approach to termination analysis of CHR. Technical report CW 506, KULCW, Leuven, Belgium, January 2008. [WWW] Keyword(s): termination.
    Abstract:
    We present a new approach to termination analysis of Constraint Handling Rules (CHR). Unlike current approaches, our approach has no restrictions on the kind of rules in the CHR program. We propose a termination condition, that verifies conditions imposed on the dynamic process of adding constraints to the store, instead of a termination argument based on the comparison of sizes of consecutive computation states. We demonstrate the condition's applicability on a set of terminating CHR programs, using a prototype analyzer. This analyzer is the first in-language automated termination analyzer for CHR programs.
    [bibtex-key = voets_pilozzi_deschreye_termination_techrep08]
  568. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. CHR$^\mathrm{rp}$: Constraint Handling Rules with rule priorties. Technical report CW 479, KULCW, Leuven, Belgium, March 2007. [WWW] Keyword(s): priorities.
    Abstract:
    We extend the Constraint Handling Rules language (CHR) with user-defined rule priorities. This language extension reduces the level of non-determinism that is inherent to the theoretical operational semantics of CHR, and gives a more high-level form of execution control compared to the refined operational semantics. We suggest some application areas. A formal operational semantics for the extended language, called CHR-rp, is given and its theoretical properties are discussed. We look at some issues with CHR-rp and discuss alternatives for rule priorities.
    [bibtex-key = dekoninck_schr_demoen_chrrp_techrep07]
  569. Leslie De Koninck, Tom Schrijvers, and Bart Demoen. The Correspondence Between the Logical Algorithms Language and CHR. Technical report CW 480, KULCW, Leuven, Belgium, March 2007. [WWW] Keyword(s): related formalisms, priorities.
    Abstract:
    This paper investigates the relationship between the Logical Algorithms language (LA) of Ganzinger and McAllester and Constraint Handling Rules (CHR). We present a translation scheme from LA to CHR-rp: CHR with rule priorities and show that the meta-complexity theorem for LA can be applied to a subset of CHR-rp via inverse translation. This result is compared with previous work. Inspired by the high-level implementation proposal of Ganzinger and McAllester, we demonstrate how LA programs can be compiled into CHR rules that interact with a scheduler written in CHR. This forms the first actual implementation of LA. Our implementation achieves the complexity required for the meta-complexity theorem to hold and can execute a subset of CHR-rp with strong complexity bounds.
    [bibtex-key = dekoninck_schr_demoen_la-chr_techrep07]
  570. Leslie De Koninck, Peter J. Stuckey, and Gregory J. Duck. Optimized compilation of CHR$^\mathrm{rp}$. Technical report CW 499, KULCW, Leuven, Belgium, August 2007. [WWW] Keyword(s): implementation, optimizing compilation, priorities.
    Abstract:
    Constraint Handling Rules were recently extended with user-definable rule priorities. This paper shows how this extended language can be efficiently compiled into the underlying host language. It extends previous work by supporting rules with a dynamic priority and by introducing various optimizations. The effects of the optimizations are empirically evaluated and the new compiler is compared with the state-of-the-art K.U.Leuven CHR system.
    [bibtex-key = dekoninck_stuck_duck_compiling-chrrp_techrep07]
  571. Paolo Pilozzi, Tom Schrijvers, and Danny De Schreye. Proving termination of CHR in Prolog: A transformational approach. Technical report CW 487, KULCW, Leuven, Belgium, April 2007. [WWW] Keyword(s): termination.
    Abstract:
    In this paper we present a termination preserving transformation from Constraint Handling Rules to Prolog. The transformation is sound w.r.t. termination under the theoretical semantics of Constraint Handling Rules. It does not consider the presence of a propagation history. The transformation allows for the direct reuse of termination proof methods from Logic Programs and Term-Rewrite Systems, yielding the first fully automatic termination proving for Constraint Handling Rules. We formalize the transformation and show usefulness of the approach. We transform a set of CHR programs, by an implementation of the transformation and show termination by using existing termination tools for Logic Programs and Term-Rewrite Systems.
    [bibtex-key = pilozzi_schr_deschreye_termination_techrep07]
  572. Beata Sarna-Starosta and Tom Schrijvers. Indexing techniques for CHR based on program transformation. Technical report CW 500, KULCW, Leuven, Belgium, August 2007. [WWW] Keyword(s): implementation, optimizing compilation.
    Abstract:
    Multi-headed rules are essential for the expressiveness of CHR, but incur a considerable performance penalty. Current indexing techniques are often unable to address this problem. They are effective only when matchings have a particular form, or offer good run-time complexity rather than good absolute figures. In this paper we describe three advanced indexing techniques: (1) two program transformations that make other indexing techniques more effective, (2) an index for ground terms more efficient than hash tables, and (3) a post-processing program transformation that eliminates runtime overhead of (1) and (2). We compare these techniques with the current state of the art, and give measurements of their effectiveness in K.U.Leuven CHR and CHRd.
    [bibtex-key = sarnastarosta_schr_indexing_techrep07]
  573. Jon Sneyers, Peter Van Weert, Tom Schrijvers, and Bart Demoen. Aggregates in CHR. Technical report CW 481, KULCW, Leuven, Belgium, March 2007. [WWW] Keyword(s): extensions.
    Abstract:
    We propose an extension of the Constraint Handling Rules language with aggregates like sum, count, findall, and min in the heads of rules. We define the semantics of aggregate expressions formally and informally. Our prototype implementation as a source-to-source preprocessor allows both on-demand and incremental computation of nested aggregate expressions over guarded conjunctions of constraints. Case studies demonstrate that by using aggregates, the program size can be significantly reduced, with only a small constant run-time overhead.
    [bibtex-key = sneyers_vanweert_et_al_aggregates_techrep07]
  574. Peter Van Weert, Jon Sneyers, Tom Schrijvers, and Bart Demoen. To $\mathrm{CHR}^{\mbox{\large$\!\!\lnot$}}$ or not to $\mathrm{CHR}^{\mbox{\large$\!\!\lnot$}}$: Extending CHR with Negation as Absence. Technical report CW 446, KULCW, Leuven, Belgium, May 2006. [WWW] Keyword(s): extensions.
    Abstract:
    In this exploratory paper, we introduce $\mathrm{CHR}^{\mbox{\large$\!\!\lnot$}}$, an extension of the CHR language with negation as absence, and we illustrate how the added expressiveness allows CHR programmers to write more declarative and concise rules. We show the difficulties of integrating negation with the conventional execution mechanism of CHR. A formal operational semantics for $\mathrm{CHR}^{\mbox{\large$\!\!\lnot$}}$ is presented, and its theoretical and practical implications are evaluated critically. We introduce a source-to-source transformation from $\mathrm{CHR}^{\mbox{\large$\!\!\lnot$}}$ to regular CHR.
    [bibtex-key = vanweert_sney_schr_demoen_negation_techrep06]
  575. Tom Schrijvers and Bart Demoen. Antimonotony-based Delay Avoidance for CHR. Technical report CW 385, KULCW, Leuven, Belgium, July 2004. [WWW] Keyword(s): implementation, optimizing compilation.
    Abstract:
    We present an optimisation for Constraint Handling Rules (CHR) that reduces the amount of variables a constraint delays on. This optimisation reduces the overhead of delaying on variables as well as the needless reawakening of delayed constraint. A correctness proof of the optimisation based on the refined operational semantics establishes the validity of the optimisation and sheds light on possible extensions as well as related optimisations. The delay avoidance optimisation shows good speedups for some programs and no noticable slowdown for others.
    [bibtex-key = schr_demoen_delay_avoid_techrep04]
  576. Martin Sulzmann. TIE: A CHR-based Type Inference Engine. Technical report TR2001/27, University of Melbourne, deptcw, 2001. Keyword(s): type systems. [bibtex-key = sulz_TIE_techrep01]
  577. Christian Holzbaur and Thom Frühwirth. Constraint Handling Rules reference manual, Release 2.2. Technical report TR-98-01, Österreichisches Forschungsinstitut für Artificial Intelligence, Wien, 1998. [bibtex-key = holz_fru_CHR_manual_techrep98]
  578. Thom Frühwirth and Pascal Brisset. High-Level Implementations of Constraint Handling Rules. Technical report ECRC-95-20, European Computer-Industry Research Centre, Munchen, Germany, 1995. [bibtex-key = fru_brisset_highlevel_implementation_techrep95]
  579. Thom Frühwirth. Temporal Reasoning with Constraint Handling Rules. Technical report ECRC-94-5, European Computer-Industry Research Centre, Munchen, Germany, 1994. [bibtex-key = fru_temporal_reasoning_techrep94]
  580. G. Dondosolla. A constraint-based implementation of the GRF. ESPRIT project no. 2409 EQUATOR Report, 1993. [bibtex-key = don_grf_93]
  581. Thom Frühwirth. Constraint Simplification Rules. Technical report ECRC-92-18, European Computer-Industry Research Centre, Munchen, Germany, July 1992. [bibtex-key = fru_constraint_simplification_rules_techrep92]
  582. Thom Frühwirth. Introducing Simplification Rules. Technical report ECRC-LP-63, European Computer-Industry Research Centre, Munchen, Germany, October 1991. Note: Presented at the Workshop Logisches Programmieren, Goosen/Berlin, Germany, October 1991 and the Workshop on Rewriting and Constraints, Dagstuhl, Germany, October 1991. [bibtex-key = fru_introducing_simplification_rules_techrep91]
  583. Falco Nogatz. CHR.js: Compiling Constraint Handling Rules to JavaScript. Master's thesis, University of Ulm, 2015. [PDF] [bibtex-key = nogatz2015chr]
  584. Rafael Caballero, Yolanda Garcia-Ruiz, and Fernando Saenz-Perez. Debugging Datalog Programs Through CHRs, 2012. [bibtex-key = caballero_debugging_datalog]
  585. Gregory M. Flanagan. Conceptual Requirement Validation for Architecture Design Systems. Master's thesis, California Polytechnic State University, San Luis Obispo, September 2011. [bibtex-key = flanagan_11]
  586. Henning Christiansen and Bo Li. Approaching the Chinese Word Segmentation Problem with CHR Grammars, September 2011. [bibtex-key = christiansen_li_chinese_word_seg_context11]
  587. T.W.D. Jongstra. Inequality Reasoning for Qualitative Models using Constraint Handling Rules. Bachelor thesis, University of Amsterdam, December 2011. [bibtex-key = jongstra_bachelorthesis11]
  588. Eric Monfroy. Constraint Handling Rules by Thom Frühwirth, Cambridge University Press, 2009, 2010. Note: Book review (to appear in Theory and Practice of Logic Programming). [doi:10.1017/S1471068410000074] [bibtex-key = monfroy_review_tplp10]
  589. Marcos Aurélio de Almeida Silva. Constraint Handling Object-oriented Rules with Disjunction (CHORD). Master's thesis, Federal University of Pernambuco, Recife, Brazil, February 2009. [WWW] Keyword(s): disjunction, search. [bibtex-key = aurelio_mastersthesis09]
  590. Adrian Kostrubiak. Integration of Java Generics Into The extttjmle Tool Within The Eclipse IDE. Honors thesis, Dickinson College, 2009. [PDF] [bibtex-key = kostrubiak_jmle_honors09]
  591. Cleyton Mário de Oliveira Rodrigues. Components and Theorem Proving with Constraint Handling Rules. Master's thesis, Federal University of Pernambuco, Recife, Brazil, 2009. [bibtex-key = mario_mastersthesis09]
  592. Mathias Wasserthal. An extensible platform for the analysis of graph transformation systems using Constraint Handling Rules. Diploma thesis, Ulm University, February 2009. Keyword(s): Graph Transformation Systems, related formalisms. [bibtex-key = wasserthal_graph_transform_thesis09]
  593. Scientific Software & Systems Ltd.. Company Profile: Solving problems with proven solutions, 2008. [WWW] [bibtex-key = sssltd_2008]
  594. Martin Magnusson. Deductive Planning and Composite Actions in Temporal Action Logic. Master's thesis, Department of Computer and Information Science, Linköping University, Sweden, 2007. Note: Thesis No. 1329. [bibtex-key = magnusson_deductive_planning_07]
  595. Ersha Rahimikia. Detecting non-termination in Constraint Handling Rules. Master's thesis, Dept. Computing and Software, McMaster University, 2007. Keyword(s): termination, termination. [bibtex-key = rahimikia_nontermination_msthesis07]
  596. Gerrit van den Geest. Constraints for Type Class Extensions. Master's thesis, Utrecht University, April 2007. Keyword(s): type systems. [bibtex-key = gvdg_type_class_extensions_mthesis07]
  597. Atze Dijkstra, Gerrit van den Geest, Bastiaan Heeren, and S. Doaitse Swierstra. Modelling Scoped Instances with Constraint Handling Rules. Note: Rejected by ICFP '07, 2007.
    Abstract:
    Haskell's class system provides a programmer with a mechanism to implicitly pass parameters to a function. A class predicate over some type variable in the type signature of a function induces the obligation for the caller to implicitly pass an appropriate instance of the class to the function. The class system is programmed by providing class instances for concrete types, thus providing, for each class, a unique mapping from types to instances. This mapping is used whenever an instance for a class predicate over some type is required. Choosing which instance to pass is solely based on the instantiated type of the class predicate. Although this mechanism has proved to be powerful enough for modelling overloading and a plethora of other programming language concepts, it is still limited in the sense that multiple instances for a type cannot exist at the same time. Usually one can program around this limitation by introducing dummy types, which act as a key to map to additional instances; but this indirect way of allowing extra instances clutters a program and still is bound to the finite number of types statically available in a program. The latter restriction makes it impossible to dynamically construct instances, which, for example, depend on runtime values. In this paper we lift these restrictions by means of local instances. Local instances allow us to shadow existing instances by new ones and to construct instances inside functions, using function arguments. We provide a translation of class and instance definitions to Constraint Handling Rules, making explicit the notion of ``scope of an instance'' and its role in context reduction for instances. We deal with the ambiguity of choosing between instances by using a framework for heuristically choosing between otherwise overlapping instances.
    [bibtex-key = dijkstra_et_al_scoped_instances_07]
  598. Maryam Bavarian. Design and analysis of biological sequences using Constraint Handling Rules. Master's thesis, Simon Fraser University, Burnaby, Canada, 2006. [WWW] Keyword(s): applications.
    Abstract:
    In this project, I test the the mean-variance Capital Asset Pricing Model (CAPM) and the Fama-French Three-Factor Model. I employ two datasets which consist of 25 portfolios formed on size and the book equity to market equity ratio and 11 portfolios formed on dividend yield. I also divide the whole period into two to consider the sub-period effects. I employ the cross-sectional tests as well as the multivariate time-series tests for both of the models. The results do not unambiguously show that one model fits better than the other. Moreover, the two sub-period results are inconsistent with each other and with the results from the whole period.
    [bibtex-key = bavarian_bio_seq_thesis_2006]
  599. Olivier Bouissou. A CHR library for SiLCC. Diplomarbeit, Technical University of Berlin, Germany, January 2005. [bibtex-key = bouissou_chr_for_silcc_2005]
  600. Hariolf Betz. A linear logic semantics for CHR. Diplomarbeit, University of Ulm, Germany, October 2004. [POSTSCRIPT] Keyword(s): semantics, linear logic. [bibtex-key = betz_mthesis04]
  601. Wei-Ngan Chin, Martin Sulzmann, and Meng Wang. A Type-Safe Embedding of Constraint Handling Rules into Haskell. Honors Thesis, School of Computing, National University of Singapore, 2003. Keyword(s): type systems, implementation. [bibtex-key = chin_sulzmann_wang_haskell_chr_03]
  602. Thomas Hecksher, Sune T.B. Nielsen, and Alexis Pigeon. A CHRG model of the ancient Egyptian grammar. Note: Unpublished student project report, Roskilde University, Denmark, December 2002. Keyword(s): applications, linguistics. [bibtex-key = roskilde_students_ancient_egyptian_grammar_02]
  603. Frank Morawietz and Philippe Blache. Parsing Natural Languages with CHR. Note: Unpublished Draft, 2002. Keyword(s): applications, linguistics. [bibtex-key = morawietz_blache_unpublished02]
  604. Ekkehard Krämer. A Generic Search Engine for a Java Constraint Kit. Diplomarbeit, Institute of Computer Science, LMU, Munich, Germany, January 2001. Keyword(s): search, Java. [bibtex-key = kr_jack:jase_2001]
  605. Matthias Schmauss. An Implementation of CHR in Java. Diplomarbeit, Institute of Computer Science, LMU, Munich, Germany, November 1999. Keyword(s): implementation, Java. [bibtex-key = schmauss_jack:jchr_1999]
  606. M. Bjareland. Proving consistency in K-IA chronicles---An implemention of PMON. Master's thesis, Dept. of Information and Comp. Science, Linkoepings Universitet, 1996. [bibtex-key = bjareland_pmon_msthesis96]
  607. Holger Meuss. Konfluenz von Constraint-Handling-Rules-Programmen. Diplomarbeit, Institut für Informatik, Ludwig-Maximilians-Universität München, Germany, 1996. Keyword(s): confluence. [bibtex-key = meuss_confluence_msthesis96]

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