Workshop Report
The third workshop on Constraint Handling Rules (CHR 2006) took place on July 9, 2006 at the occasion of the 33rd ICALP conference. Previous workshops were organised at the occasion of ICLP 2005 in Sitges, Spain and in Ulm, Germany in 2004. Last year's success was continued this year with a program of 9 accepted papers out of 11 submitted papers. All papers had received at least two reviews and most even three.
The workshop venue was the lovely San Servolo island in Venice, Italy. About 20 attendants listened to presentations on diverse topics ranging from semantics and theoretical properties such as confluence and complexity, over language features and implementation to constraint solvers and agent programming. In addition, we were honoured to have an invited talk by Kazunori Ueda (Waseda University, Tokyo, Japan) on his LMNtal language, which is closely related to CHR. The co-located PPDP symposium was also of special interest: its program featured two papers on type inference with CHR and an invited talk on the "Story So Far" by CHR's designer Thom Fruehwirth.
We would like to thank all the authors, participants and PC members for their support and contributions. Special thanks go to the local organisers, Michele Bugliesi and his team, and Alessandra Raffaeta, who has organised our workshop dinner in Osteria Paradiso Perduto on the eventful night of Italy's victory in the soccer championship.
Next year there will of course be a fourth installment of the CHR workshop. It is to early to reveal anything about the date and time of CHR 2007, but we are already looking forward to see you there.
Tom Schrijvers
Proceedings
The workshop proceedings have been published as a technical report.Important dates
- submission deadline: May 7, 2006
- notification of acceptance: CHANGED: May 29, 2006
- final version due: June 23, 2006
- workshop date: July 9, 2006
CHR 2006 Preliminary Programme - July 9, 2006
| 09:15 - 09:30 | Workshop Opening |
| 9:30 - 10:00 |
Representing Linear-Logic Agents in CHR Edmund S. L. Lam, Martin Sulzmann |
| 10:00 - 10:30 | Coffee Break |
| 10:30 - 11:30 |
Invited Talk by Kazunori Ueda, Waseda University, Japan LMNtal as a Unifying Declarative Language |
| 11:30 - 12:00 |
Implementation of an F-Logic Kernel in CHR Martin Kaeser, Marc Meister |
| 12:00 - 12:30 |
Deriving Linear-Time Algorithms from Union-Find in CHR Thom Frühwirth |
| 12:30 - 14:30 | Lunch Break |
| 14:30 - 15:00 |
Observable Confluence for Constraint Handling Rules Gregory J. Duck, Peter J. Stuckey, Martin Sulzmann |
| 15:00 - 15:30 |
Complexity of the CHR Rational Tree Equation Solver Marc Meister, Thom Frühwirth |
| 15:45 - 16:15 |
A Compositional Semantics for CHR with Propagation Rules Maurizio Gabbrielli, Maria Chaira Meo, Paolo Tacchella |
| 16:00 - 16:30 | Coffee Break |
| 16:30 - 17:00 |
Search Strategies in CHR(Prolog) Leslie De Koninck, Tom Schrijvers, Bart Demoen |
| 17:00 - 17:30 |
Constraint Handling Rules with Negations as Absence Peter Van Weert, Jon Sneyers, Tom Schrijvers, Bart Demoen |
| 17:30 - 18:00 |
Translating Constraint Handling Rules into Action Rules Tom Schrijvers, Neng-Fa Zhou, Bart Demoen |
| 18:00 - 18:15 | Discussion and Workshop Closing |
Invited Talk
LMNtal as a Unifying Declarative Language, Kazunori Ueda, Waseda University
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 (also known as concurrent constraint programming) 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 talk, 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 and their future directions in the hope that it will promote cross-fertilization of ideas and results we have accumulated.
Registration
Registration for the CHR 2006 workshop is possible through the ICALP/PPDP/LOPSTR'06 and affiliated Workshops registration page. Early registration ends on May 31.Introduction
The Constraint Handling Rules (CHR) language has become a major declarative specification and implementation language for constraint-based algorithms and applications. Algorithms are often specified using inference rules, rewrite rules, sequents, proof rules or logical axioms that can be directly written in CHR. Its clean semantics facilitates program design, analysis and transformation. See the CHR website for more information.
The First Workshop on Constraint Handling Rules was organized in May 2004 in Ulm, Germany. In October 2005 the Second Workshop on Constraint Handling Rules was organized at the occasion of ICLP 2005 in Sitges, Spain.
Topics of Interest
The workshop calls for full papers and short papers describing ongoing work, on all aspects of CHR, including topics such as:
- (Logical) Algorithms
- Applications
- Comparisons with Related Approaches
- Constraint Solvers
- Critical Assessment
- Expressivity and Complexity
- Implementations and Optimization
- Language Extensions (Types, Modules)
- Program Analysis
- Program Transformation and Generation
- Programming Environments (Debugging)
- Programming Pearls
- Retractable Constraints
- Semantics
The call for papers is avaibale here.
Best Paper Award
The best paper receives the CHR Best Paper Award. It is chosen among all submissions for its outstanding quality in both presentation and scientific contribution and for its impact on the field of CHR.
The 2005 CHR Best Paper Award went to:
Jon Sneyers, Tom Schrijvers, Bart Demoen
Submission Information
All papers must be written in English and not exceed 15 pages in Springer LNCS format. The authors are encouraged, although not obliged, to submit their papers already in Springer LNCS format. General information about the Springer LNCS series and the LNCS authors' instructions are available at the Springer LNCS/LNAI home page.
Submissions should be sent to chrworkshop@gmail.com and mention 'CHR 2006 Submission' in the subject. Every submission should include the names and e-mail addresses of the authors (with the corresponding author indicated), the paper abstract in ASCII format and the actual paper in postscript or PDF format. The submission should also indicate whether it is a full paper or a short paper.
Accepted papers will be published in a technical report.
Organization
Program Committee:
- Alessandra Raffaeta, Universita Ca' Foscari di Venezia
- François Fages, INRIA Rocquencourt
- Gregory Duck, NICTA Victoria Laboratory
- Henning Christiansen, Roskilde University
- Jacques Robin, Universidade Federal de Pernambuco
- Martin Sulzmann, National University of Singapore
- Maurizio Gabbrielli, Universita di Bologna
- Slim Abdennadher, German University in Cairo
Workshop Coordinators:
|
Tom Schrijvers (contact person)
|
Thom Frühwirth
|