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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2011

45.
Langbein, Johannes; Stelzer, Roland; Frühwirth, Thom
A Rule-Based Approach to Long-Term Routing for Autonomous Sailboats
In Schlaefer, A. and Blaurock, O., Editor, Robotic Sailing: Proceedings of the 4th International Robotic Sailing Conference, Page 195-204
In Schlaefer, A. and Blaurock, O., Editor
Publisher: Springer-Verlag
2011
DOI:10.1007/978-3-642-22836-0_14
44.
Raiser, Frank; Frühwirth, Thom
Analysing graph transformation systems through constraint handling rules
Theory and Practice of Logic Programming, 11 (1) :65-109
January 2011
DOI:10.1017/S1471068410000438

2010

43.
Betz, Hariolf; Raiser, Frank; Frühwirth, Thom
A Complete and Terminating Execution Model for Constraint Handling Rules
Theory and Practice of Logic Programming, 10 (4-6) :597-610
July 2010
DOI:10.1017/S147106841000030X
42.
Langbein, Johannes; Raiser, Frank; Frühwirth, Thom
A State Equivalence and Confluence Checker for CHR
In Van Weert, P. and De Koninck, L., Editor, Proceedings of the 7th International Workshop on Constraint Handling RulesfromReport, Page 1-7
In Van Weert, P. and De Koninck, L., Editor
Publisher: Departement of Computer Science, Katholieke Universiteit Leuven
May 2010
41.
Geiselhart, Florian; Raiser, Frank; Sneyers, Jon; Frühwirth, Thom
MTSeq: Multi-touch-enabled CHR-based Music Generation and Manipulation
In Van Weert, P. and De Koninck, L., Editor, Proceedings of the 7th International Workshop on Constraint Handling RulesfromReport, Page 41-46
In Van Weert, P. and De Koninck, L., Editor
Publisher: Departement of Computer Science, Katholieke Universiteit Leuven
May 2010
40.
Betz, Hariolf; Raiser, Frank; Frühwirth, Thom
Persistent Constraints in Constraint Handling Rules
In Geske, U. and Wolf, A., Editor, Proceedings of the 23rd Workshop on (Constraint) Logic Programming 2009, Page 155-166
In Geske, U. and Wolf, A., Editor
Publisher: Universitätsverlag Potsdam
March 2010
39.
Betz, Hariolf; Raiser, Frank; Frühwirth, Thom
A Complete and Terminating Execution Model for Constraint Handling Rules
from Ulmer Informatik-Berichte
Document Number: 2010-01
Universität Ulm
January 2010

2009

38.
Raiser, Frank; Frühwirth, Thom
Strong Joinability Analysis for Graph Transformation Systems in CHR
In Corradini, A., Editor, Proceedings of the Fifth International Workshop on Computing with Terms and Graphs (TERMGRAPH 2009)Volume253fromElectronic Notes in Theoretical Computer Science, Page 91-111
In Corradini, A., Editor
November 2009
DOI:10.1016/j.entcs.2009.10.019
37.
Raiser, Frank; Betz, Hariolf; Frühwirth, Thom
Equivalence of CHR States Revisited
In Raiser, F. and Sneyers, J., Editor, CHR 2009: Proceedings of the Sixth International Workshop on Constraint Handling RulesfromTechnical Report, Page 34-48
In Raiser, F. and Sneyers, J., Editor
Publisher: Departement Computerwetenschappen, Katholieke Universiteit Leuven
July 2009
36.
Raiser, Frank; Frühwirth, Thom
Operational Equivalence of Graph Transformation Systems
In Raiser, F. and Sneyers, J., Editor, CHR 2009: Proceedings of the Sixth International Workshop on Constraint Handling RulesfromTechnical Report, Page 49-61
In Raiser, F. and Sneyers, J., Editor
Publisher: Departement Computerwetenschappen, Katholieke Universiteit Leuven
July 2009