Institute of Software Engineering and Programming Languages

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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2009

35.
Raiser, Frank; Frühwirth, Thom
Strong joinability analysis for graph transformation systems in CHR
In Corradini, A., Editor, Preliminary Proceedings of the 5th International Workshop on Computing with Terms and Graphs (TERMGRAPH), Page 97-112
In Corradini, A., Editor
2009
DOI:10.1016/j.entcs.2009.10.019
34.
Frühwirth, Thom
Constraint Handling Rules
Publisher: Cambridge University Press
2009

2008

33.
Raiser, Frank; Frühwirth, Thom
Towards Term Rewriting Systems in Constraint Handling Rules
In Schrijvers, T. and Raiser, F. and Frühwirth, T., Editor, CHR 2008, The 5th Workshop on Constraint Handling Rules, Page 19-33
In Schrijvers, T. and Raiser, F. and Frühwirth, T., Editor
July 2008
32.
Sneyers, Jon; Frühwirth, Thom
Generalized CHR Machines
In Schrijvers, T. and Raiser, F. and Frühwirth, T., Editor, CHR 2008, The 5th Workshop on Constraint Handling Rules, Page 143-157
In Schrijvers, T. and Raiser, F. and Frühwirth, T., Editor
July 2008
31.
Djelloul, Khalil; Dao, T.-B.-H.; Frühwirth, Thom
Theory of finite or infinite trees revisited
Theory and Practice of Logic Programming, 8 (4) :431-489
July 2008
DOI:10.1017/S1471068407003171
30.
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
29.
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

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