GLP e.V.GI e.V.

WLP 2009

23rd Workshop on (Constraint) Logic Programming

Potsdam, Germany
September 15/16, 2009

Co-located with LPNMR'09 - 10th International Conference on Logic Programming and  Nonmonotonic Reasoning

Preliminary Workshop Program and Papers added!

General | Topics | Proceedings | Submission | Dates | Program | Invited TalksRegistration | Local Info | Program Committee | Contact


The workshops on (constraint) logic programming are the annual meeting of the Society of Logic Programming (GLP e.V.) and bring together researchers interested in logic programming, constraint programming, and related areas like databases, artificial intelligence and operations research. Previous workshops have been held in Germany, Austria and Switzerland. The technical program of the workshop will include an invited talk, presentations of refereed papers and demo presentations.

Previous workshops took place in Dresden (2008), Würzburg (2007), Vienna (2006), Ulm (2005), Potsdam (2004), Dresden (2002), Kiel (2001),...

Call for Papers


Contributions are welcome on all theoretical, experimental, and application aspects of constraint programming (CP) and logic programming (LP), including, but not limited to (the order does not reflect priorities): The primary focus is on new and original research results but submissions describing innovative products, prototypes under development,  interesting experiments (e.g., benchmarks) or ongoing scientific work are also encouraged.


The proceedings are published as a technical report of the Institute of Computer Science, Potsdam University.
They are online available. Moreover, a printed version of the proceedings is available, too:

    Ulrich Geske; Armin Wolf (eds.): Procceedings of the 23rd Workshop on (Constraint)
    Logic Programming 2009, Universitätsverlag Potsdam, 2010. ISBN 978-3-86956-026-7.

Copies can be ordered at the Universitätsverlag Potsdam.


Authors are invited to submit an extended abstract (no longer than 10 pages including figures and references) or a system description (no longer than 3 pages) in PDF or Postscript format (11pt) before August  09, 2009 via EasyChair. All submissions must be written in English. Authors are strongly encouraged to use LaTeX2e and the Springer llncs class file, available here.
All submissions must be unpublished original work. However, work that already appeared in unpublished or informally published workshops proceedings may be submitted, too.

If you have any problems with submitting papers, please send an email to or

 Important Dates

Submission of papers: August   9, 2009 (closed)
Notification of acceptance: August 21, 2009 (closed)
Camera-ready papers: September 10, 2009 (closed)
Workshop: September 15/16, 2009 (accomplished)
Ready-for-printing papers:October  16, 2009 (closed)

 Program (NEW: with Links to the Publications)

Thuesday, September 15

08:30 - 09:30 Invited Talk at LPNMRIlkka Niemelä: Integrating Answer Set Programming and Satisfiability Modulo Theories
09:30 - 10:20 DatabasesMichael Hanus and Sven Koschnicke: An ER-based Framework for Declarative Web Programming  
Dietmar Seipel. Practical Applications of Extended Deductive Databases in Datalog^s   
10:20 - 10:40 Coffee Break 
10:40 -11:55 Answer Set ProgrammingMartin Gebser, Henrik Hinrichs, Torsten Schaub and Sven Thiele: xpanda: A (Simple) Preprocesser for Adding Multi-valued Propositions to ASP
Pedro Cabalar: Existential Quantifiers in the Rule Body   
Johannes Oetsch, Martin Schwengerer and Hans Tompits: Kato: A Plagiarism-Detection Tool for Answer-Set Programs
11:55 - 12:20 Theory of Logic ProgrammingHeinrich Herre and Axel Hummel: A Paraconsistent Semantics for Generalized Logic Programs
12:20 - 13:30 Lunch Break 
13:30 - 14:20 Invited Talk at WLPNeng-Fa Zhou: What I have learned from all these solver competitions
14:20 - 15:35 Theory (of Logic Programming)Heinrich Herre and Axel Hummel: Stationary Generated Models of Generalized Logic Programs
Gourinath Banda and John Gallagher: Constraint-Based Abstraction of a Model Checker for Infinite State Systems
Stefan Brass: Range Restriction for General Formulas
15:35 - 16:00 Coffee Break                                                                                                                                                    
16:00 -17:15 GLP Meeting 
17:20 - ... Sanssouci Tour 

Wednesday, September 16

08:30 - 09:30 Invited Talk at WLPTom Schrijvers: Overview of the Monadic Constraint Programming Framework
09:30 - 10:20 Constraint Handling RulesSlim Abdennadher, Haythem Ismail and Frederick Khoury: Transforming Imperative Algorithms to Constraint Handling Rules   
Hariolf Betz, Frank Raiser and Thom Fruehwirth: Persistent Constraints in Constraint Handling Rules
10:20 - 10:40 Coffee Break                                                                                                                                                                                                                                                           
10:40 - 11:30 Practice of Logic ProgrammingHans-Joachim Goltz and Norbert Pieth: A Tool for Generating Partition Schedules of Multiprocessor Systems     
Ulrich Geske and Hans-Joachim Goltz: Efficiency of Difference-List Programming

... continued in the LPNMR'09 program

 Invited Talks

on an "Overview of the Monadic Constraint Programming Framework" by Tom Schrijvers (KU Leuven, Belgium)

A constraint programming system combines two essential components: a constraint solver and a search engine. The constraint solver reasons about satisfiability of conjunctions of constraints, and the search engine controls the search for solutions by iteratively exploring a  disjunctive search tree defined by the constraint program.
The Monadic Constraint Programming framework gives a monadic definition of constraint programming where the solver is defined as a monad threaded through the monadic search tree. Search and search strategies can then be defined as firstclass objects that can themselves be built or extended by composable search transformers. Search transformers give a powerful and unifying approach to viewing search in constraint programming, and the resulting constraint programming system is first class and extremely flexible.

on "What I have learned from all these solver competitions" by Neng-Fa Zhou (City University of New York, USA)

In this talk, I would like to share my experiences gained from participating in four CSP competitions and the second ASP solver competition. In particular, I'll talk about how various programming techniques can make huge differences in solving some of the benchmark problems used in the competitions. These techniques include global constraints, table constraints, and problem-specific propagators and labeling strategies for selecting variables and values. I'll present these techniques with experimental results from B-Prolog and other CLP(FD) systems.

Further Invited Talks at LPNMR'09

Moreover, there is the opportunity to participate in the invited talks at LPNMR'09 given by 


To register for WLP 2009 please consider the LPNMR'09 registration information and its registration form.

 Local Info

For information on travel please consider LPNMR'09 "Getting to Potsdam" and for accommodation suggestions visit the LPNMR'09 accommodation web page.

 Program Committee

Slim Abdennadher (German University Cairo)  
Christoph Beierle (FernUniv. Hagen)
Stefan Brass (MLU Halle-Wittenberg)  
Jürgen Dix (Clausthal University of Technology)
Tim Furche (LMU München)
Ulrich Geske (Univ. Potsdam, Speaker FG 1.1.1.)
Hans-Joachim Goltz (Fraunhofer FIRST)
Michael Hanus (CAU Kiel)
Heinrich Herre (Univ. Leipzig)  
Steffen Hölldobler (TU Dresden)

Petra Hofstedt (TU Berlin)
Ulrich John (SIR Plan GmbH)
Michael Leuschel (Univ. Düsseldorf)
Ulrich Neumerkel (TU Wien)
Frank Raiser (Univ. Ulm)

Georg Ringwelski (Hochschule Zittau/Görlitz)

Sibylle Schwarz (Hochschule Zwickau) 
Dietmar Seipel (Univ. Würzburg)
Michael Thielscher (TU Dresden)
Hans Tompits (TU Wien)
Armin Wolf (Fraunhofer FIRST)

 Chairs (contact)

Dr. Armin Wolf


Fraunhofer-Institut für Rechnerarchitektur
und Softwaretechnik, FIRST
Kekuléstraße 7
12489 Berlin
Prof. Dr. Ulrich Geske


Universität Potsdam

Institut für Informatik

Haus 4
August-Bebel-Straße 89
14482 Potsdam

Armin Wolf,