Joint Workshop on

Implementation of Constraint Logic Programming Systems


Logic-based Methods in Programming Environments

Satellite event of ICLP 2010
Edinburgh, Scotland, U.K.
July 15, 2010

Workshop description

CICLOPS is a series of colloquia on the implementation of constraint logic programming. Logic and Constraint programming is an important declarative programming paradigm. The features offered by this paradigm such as rule-basedness, pattern matching, automated backtracking, recursion, tabling, and constraint solving have been proved convenient for many programming tasks. Recent improvements in implementation technologies combined with advances in hardware and systems software have made logic and constraint programming a viable choice for many real-world problems.

CICLOPS'10 continues a tradition of successful workshops on Implementations of Logic Programming Systems, previously held with in Budapest (1993) and Ithaca (1994), the Compulog Net workshops on Parallelism and Implementation Technologies held in Madrid (1993 and 1994), Utrecht (1995) and Bonn (1996), the Workshop on Parallelism and Implementation Technology for (Constraint) Logic Programming Languages held in Port Jefferson (1997), Manchester (1998), Las Cruces (1999), and London (2000), and more recently the Colloquium on Implementation of Constraint and LOgic Programming Systems in Paphos (Cyprus, 2001), Copenhagen (2002), Mumbai (2003), Saint Malo (France, 2004), Sitges (Spain, 2005), Seattle (U.S.A., 2006), Porto (Portugal, 2007), Udine (Italy, 2008), and Pasadena (U.S.A, 2009).

WLPE is a series of workshops on practical logic-based software development methods and tools. Software plays a crucial role in modern society. While software keeps on growing in size and complexity, it is more than ever required to be delivered on time, free of error and meeting the most stringent efficiency requirements. Thus more demands are placed on the software developer, and consequently, the need for methods and tools that support the programmer in every aspect of the software development process is widely recognized. Logic plays a fundamental role in analysis, verification and optimization in all programming languages, not only in those based directly on logic. The use of logic-based techniques in software development is a very active area in computing; emerging programming paradigms and growing complexity of the properties to be verified pose new challenges for the community, while emerging reasoning techniques can be exploited.

WLPE'10 continues the series of successful international workshops on logic programming environments held in Ohio, USA (1989), Eilat, Israel (1990), Paris, France (1991), Washington D.C., USA (1992), Vancouver, Canada (1993), Santa Margherita Ligure, Italy (1994), Portland, USA (1995), Leuven, Belgium (1997), Las Cruces, USA (1999), Paphos, Cyprus (2001), Copenhagen, Denmark (2002), Mumbai, India (2003), Saint Malo, France (2004), Sitges (Barcelona), Spain (2005), Seattle, USA (2006), Porto, Portugal (2007) and Udine, Italy (2008). More information about the series of WLPE workshops can be found at

CICLOPS-WLPE 2010 aims at bringing together, in an informal setting, people involved in research in the design and implementation of logic and constraint programming languages and systems and on logic-based methods and tools which support program development and analysis. In addition to papers describing more conceptual and theoretical work, papers describing the implementation of, and experience with, such tools will be welcome.

Topics include, but are not limited to:

Authors who are interested in taking part in the workshop, but are unsure if their work falls within its scope, are invited to contact the organizers and will be given suitable advice.

Important Dates

Paper Submission:March 31, 2010
Notification of Authors:April 29, 2010
Camera-ready:May 17, 2010
Conference:July 15, 2010

Invited speakers

Michael Codish, Ben-Gurion University of the Negev (Israel)

Programming with Boolean Satisfaction

In recent years, research on Boolean satisfiability (SAT) is generating remarkably powerful SAT solvers capable of handling larger and larger SAT instances. With the availability of progressively stronger SAT solvers, an accumulating number of applications have been developed which demonstrate that real world problems can often be solved by encoding them into SAT. One of the success stories is the application to termination analysis where we aim to automatically provide proofs of termination for software. Here, in the past five years, Boolean satisfiability has completely revolutionized the field.

One major obstacle in applying SAT solving to a given problem is to devise a suitable representation of the problem. This involves mapping the problem to a propositional formula in such a way that a model of the formula represents a solution of the original problem. This activity is just like programming (with logic): variables are Booleans and programs are formulas in conjunctive normal form. With expertise in declarative, logic and constraint programming, our community is well situated to join efforts in the development of new SAT encoding techniques and new applications for SAT solving. In this talk I will survey several SAT encoding techniques which come up in the application to termination analysis as well as in other applications.

Naoyuki Tamura, Kobe University (Japan)

Solving Constraint Satisfaction Problems by a SAT Solver
(joint work with Tomoya Tanjo and Mutsunori Banbara, Kobe University, Japan)

A Boolean Satisfiability Testing Problem (SAT) is a combinatorial problem to find a Boolean variable assignment which satisfies all given Boolean formulas. Recent performance improvement of SAT technologies makes SAT-based approaches applicable for solving hard and practical combinatorial problems, such as planning, scheduling, hardware/software verification, and constraint satisfaction,

Sugar is a SAT-based constraint solver based on a new encoding method called order encoding which was first used to encode job-shop scheduling problems by Crawford and Baker. In the order encoding, a comparison x<=a is encoded by a different Boolean variable for each integer variable x and integer value a. The Sugar solver shows a good performance for a wide variety of problems, and became the winner of the GLOBAL categories in 2008 and 2009 CSP solver competitions.

The talk will provide an introduction to modern SAT solvers, SAT encodings, implementation techniques of the Sugar solver, and its performance evaluation.

Programm committee

Rafael CaballeroComplutense University Madrid, Spain
Vitor Santos CostaUniversidade do Porto, Portugal
Martin GebserUniversity of Potsdam, Germany
Samir GenaimComplutense University of Madrid, Spain
Yoshitaka KameyaTokyo Institute of Technology, Japan
Andy KingUniversity of Kent, UK
Huiqing LiUniversity of Kent, U.K.
Lunjin LuOakland University, MI, USA
Paulo MouraUniversidade da Beira Interior, Portugal
Ulrich NeumerkelTechnische Universit¨t Wien, Austria
Enrico PontelliNew Mexico State University, USA
Joachim SchimpfMonash University, Australia
Peter Schneider-KampUniversity of Southern Denmark, Denmark
Wim VanhoofUniversity of Namur, Belgium
German Vidal (co-chair)Technical University of Valencia
Neng-Fa Zhou (co-chair)The City University of New York, NY, USA


Informal proceedings will be published as a technical report and distributed at the workshop, as well as electronically at the Computing Research Repository (CoRR).

Submission Guidelines

All papers must describe original, previously unpublished research, and must not simultaneously be submitted for publication elsewhere. They must be written in English. Papers must not exceed 15 pages in the Springer LNCS format.

Papers should follow the Springer LNCS format and be submitted electronically at

Workshop Program

Thursday, July 15th

09:00‑10:00 Invited Talk (Chair: Neng-Fa Zhou)
10:00‑10:30 Coffee break

10:30‑12:30 Session 2
12:30‑14:00 Lunch

14:00‑15:00 Invited talk(Chair: German Vidal) 15:00‑15:30 Coffee break

15:30‑18:00 Session 4

Online proceedings

The Proceedings of CICLOPS-WLPE 2010 have been published electronically at the Computing Research Repository (CoRR).