CHR Research Group

Constraint Handling Rules (CHR) is a concurrent committed-choice constraint logic programming language consisting of guarded rules that transform multi-sets of atomic formulas (constraints) until exhaustion. It was designed by Thom Fruehwirth in 1991. CHR can embed many rule-based formalisms and systems, and it can describe algorithms in a compact declarative way without compromising efficiency. The clean semantics of CHR ensures that several desirable properties hold for CHR programs and also facilitates sophisticated program analysis. CHR libraries exist for Prolog, Haskell, Java, Javascript, Python and C. CHR is also available online for experimentation with many example programs. More than 250 academic and industrial projects worldwide use CHR, and about 2500 research papers reference it.

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2008

30.
Frühwirth, Thom
Quasi-Linear-Time Algorithms by Generalisation of Union-Find in CHR
In Fages, F. and Rossi, F. and Soliman, S., Editor, Recent Advances in Constraints: 12th Annual ERCIM Workshop on Constraint Solving and Constraint Logic Programming, CSCLP 2007Volume5129fromLecture Notes in Computer Science, Page 91-108
In Fages, F. and Rossi, F. and Soliman, S., Editor
Publisher: Springer-Verlag
2008
DOI:10.1007/978-3-540-89812-2_7
29.
Frühwirth, Thom
Welcome to Constraint Handling Rules
In Schrijvers, T. and Frühwirth, T., Editor, Constraint Handling Rules: Current Research TopicsVolume5388fromLecture Notes in Computer Science, Page 1-15
In Schrijvers, T. and Frühwirth, T., Editor
Publisher: Springer-Verlag
2008
DOI:10.1007/978-3-540-92243-8_1

2007

28.
Frühwirth, Thom
Description Logic and Rules the CHR Way
In Djelloul, K. and Duck, G. J. and Sulzmann, M., Editor, Proceedings of the 4th Workshop on Constraint Handling Rules, CHR 2007, Page 49-61
In Djelloul, K. and Duck, G. J. and Sulzmann, M., Editor
September 2007
27.
Meister, Marc; Frühwirth, Thom
Reconstructing almost-linear Tree Equation Solving Algorithms in CHR
In Fages, F. and Rossi, F. and Soliman, S., Editor, Constraint Solving and Constraint Logic Programming, 12th Annual ERCIM Workshop, Page 123-137
In Fages, F. and Rossi, F. and Soliman, S., Editor
June 2007
26.
Meister, Marc; Djelloul, Khalil; Frühwirth, Thom
Complexity of a CHR Solver for Existentially Quantified Conjunctions of Equations over Trees
In Azevedo, F. and Barahona, P. and Fages, F. and Rossi, F., Editor, Recent Advances in Constraints: 11th Annual ERCIM Workshop on Constraint Solving and Constraint Logic Programming, CSCLP 2006Volume4651fromLecture Notes in Computer Science, Page 139-153
In Azevedo, F. and Barahona, P. and Fages, F. and Rossi, F., Editor
Publisher: Springer-Verlag
2007
25.
Djelloul, Khalil; Dao, T.-B.-H.; Frühwirth, Thom
Toward a first-order extension of Prolog's unification using CHR: a CHR first-order constraint solver over finite or infinite trees
In Hung, C. C. and Rosa, A., Editor, Proceedings of the 2007 ACM symposium on Applied computing, SAC 2007, Page 58-64
In Hung, C. C. and Rosa, A., Editor
Publisher: ACM Press
2007
DOI:10.1145/1244002.1244016

2006

24.
Meister, Marc; Frühwirth, Thom
Complexity of the CHR Rational Tree Equation Solver
In Schrijvers, T. and Frühwirth, T., Editor, Proceedings of CHR 2006, Third Workshop on Constraint Handling RulesfromTechnical Report, Page 77-92
In Schrijvers, T. and Frühwirth, T., Editor
Publisher: Departement Computerwetenschappen, Katholieke Universiteit Leuven
June 2006
23.
Frühwirth, Thom
Deriving Linear-Time Algorithms from Union-Find in CHR
In Schrijvers, T. and Frühwirth, T., Editor, Proceedings of CHR 2006, Third Workshop on Constraint Handling RulesfromTechnical Report, Page 49-60
In Schrijvers, T. and Frühwirth, T., Editor
Publisher: Departement Computerwetenschappen, Katholieke Universiteit Leuven
June 2006
22.
Schrijvers, T.; Demoen, B.; Duck, G.; Stuckey, P.; Frühwirth, Thom
Automatic implication checking for CHR constraints
In Cirstea, H. and Martí-Oliet, N., Editor, Proceedings of the 6th International Workshop on Rule-Based Programming, RULE 2005Volume147fromElectronic Notes in Theoretical Computer Science, Page 93-111
In Cirstea, H. and Martí-Oliet, N., Editor
January 2006
21.
Frühwirth, Thom
Complete Propagation Rules for Lexicographic Order Constraints over Arbitrary Domains
In Hnich, B. and Carlsson, M. and Fages, F. and Rossi, F., Editor, Recent Advances in Constraints, CSCLP 2005Volume3978fromLecture Notes in Computer Science, Page 14-28
In Hnich, B. and Carlsson, M. and Fages, F. and Rossi, F., Editor
Publisher: Springer-Verlag
2006
DOI:10.1007/11754602_2