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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2018

87.
Sharaf, Nada; Abdennadher, Slim; Frühwirth, Thom
CHRvis: Syntax and Semantics
Technical Communications of the 34th International Conference on Logic Programming (ICLP 2018)
34th International Conference on Logic Programming (ICLP 2018)
Oxford, UK
July 2018
July 2018
86.
Frühwirth, Thom
A Rule-Based Tool for Analysis and Generation of Graphs Applied to Mason's Marks
Proceedings of the Workshop on Logic and Practice of Programming (LPoP 2018)
Workshop on Logic and Practice of Programming (LPoP 2018)
Oxford, UK
2018-07-18
July 2018
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.170/home/gall/publications/fru_masonmarks-short-final.pdf
85.
Frühwirth, Thom
Security Policies in Constraint Handling Rules
Proceedings of the Workshop on Logic and Practice of Programming (LPoP 2018)
Workshop on Logic and Practice of Programming (LPoP 2018)
Oxford, UK
2018-07-18
July 2018
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.170/home/gall/publications/fru_rbac-chr-final.pdf
84.
Gall, Daniel; Frühwirth, Thom
Confluence Modulo Equivalence with Invariants in Constraint Handling Rules
In Gallagher J., Sulzmann M., Editor, Functional and Logic ProgrammingVolume10818fromLecture Notes in Computer Science, Page 116-131
Fourteenth International Symposium on Functional and Logic Programming 2018 (FLOPS 2018)
Nagoya, Japan
In Gallagher J., Sulzmann M., Editor
Publisher: Springer
May 2018
DOI:10.1007/978-3-319-90686-7_8
File:https://arxiv.org/abs/1802.03381
83.
Frühwirth, Thom
Justifications in Constraint Handling Rules for Logical Retraction in Dynamic Algorithms
In Fabio Fioravanti and John P. Gallagher, Editor, Revised Selected Papers of the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017)Volume10855
LOPSTR 2017
Namur, Belgium
In Fabio Fioravanti and John P. Gallagher, Editor
Publisher: Springer
2018
File:pdfhttp://www.informatik.uni-ulm.de/pm/mitarbeiter/fruehwirth/drafts/chr-justifications-lopstr-lncs-0.pdf
82.
Sharaf, Nada; Abdennadher, Slim; Frühwirth, Thom
Using Rules for the Visualization of Tableaux Proof Techniques for Propositional Logic
Proceedings of the 22nd International Conference Information Visualisation (iV2018)
22nd International Conference Information Visualisation (iV2018)
Salerno, Italy
July 2018
2018

2017

81.
Frühwirth, Thom
Justifications in Constraint Handling Rules for Logical Retraction in Dynamic Algorithms
Pre-proceedings paper presented at the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur, Belgium, 10-12 October 2017 (arXiv:1708.07854)
27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017)
Namur, Belgium
10-12 October 2017
October 2017
File:http://arxiv.org/abs/1706.07946
80.
Richter, Frank; Gall, Daniel; Frühwirth, Thom
A Confluence Checker for Constraint Handling Rules with Persistent Constraints
Proceedings of the 21st International Conference on Applications of Declarative Programming and Knowledge Management (INAP)
21st International Conference on Applications of Declarative Programming and Knowledge Management (INAP)
Würzburg
19th to 21st September 2017
September 2017
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.170/home/gall/publications/richter_gall_fru_inap_2017.pdf
79.
Frühwirth, Thom
Implementation of Logical Retraction in Constraint Handling Rules with Justifications
Proceedings of the 21st International Conference on Applications of Declarative Programming and Knowledge Management (INAP)
21st International Conference on Applications of Declarative Programming and Knowledge Management (INAP)
Würzburg
19th to 21st September 2017
September 2017
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.170/home/fruehwirth/publications/2017_fru_inap.pdf
78.
Gall, Daniel; Frühwirth, Thom
A Decidable Confluence Test for Cognitive Models in ACT-R
In Stefania Costantini, Enrico Franconi, William Van Woensel, Roman Kontchakov, Fariba Sadri, and Dumitru Roman, Editor, Proceedings of RuleML+RR 2017Volume10364fromLecture Notes in Computer Science
International Joint Conference on Rules and Reasoning (RuleML+RR 2017)
London, UK
July 2017
In Stefania Costantini, Enrico Franconi, William Van Woensel, Roman Kontchakov, Fariba Sadri, and Dumitru Roman, Editor
Publisher: Springer
July 2017
DOI:10.1007/978-3-319-61252-2_9
File:http://arxiv.org/pdf/1705.08392