Recent Advances in Constraints: Joint ERCIM/CologNet International Workshop on Constraint Solving and Constraint Logic Programming Cork, Ireland, June 19–21, 2002. Selected Papers

209 Pages·2003·2.344 MB·English

by  Manuel Hermenegildo, Germán Puebla, Francisco Bueno (auth.), Barry O’Sullivan (eds.)

Lecture Notes in Artificial Intelligence 2627
SubseriesofLectureNotesinComputerScience
EditedbyJ.G.CarbonellandJ.Siekmann
Lecture Notes in Computer Science
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Barry O’Sullivan (Ed.)
Recent Advances
in Constraints
Joint ERCIM/CologNet International Workshop on
Constraint Solving and Constraint Logic Programming
Cork, Ireland, June 19-21, 2002
Selected Papers
1 3
SeriesEditors
JaimeG.Carbonell,CarnegieMellonUniversity,Pittsburgh,PA,USA
Jo¨rgSiekmann,UniversityofSaarland,Saarbru¨cken,Germany
VolumeEditor
BarryO’Sullivan
DepartmentofComputerScience
UniversityCollegeCork,Ireland
E-mail:[email protected]
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Preface
This volume contains a selection of papers from the Joint ERCIM/CologNet
Workshop on Constraint Solving and Constraint Logic Programming, held at
the Cork Constraint Computation Centre from the 19th to the 21st of June
2002. The workshop co-located two events: the seventh meeting of the ERCIM
Working Group on Constraints, co-ordinated by Krzysztof Apt, and the first
annual workshop of the CologNet Area for Constraint and Logic Programming,
co-ordinated by Francesca Rossi.
The aim of this workshop was to provide a forum where researchers in con-
straintprocessingcouldmeetinaninformalsettinganddiscusstheirmostrecent
work.TheCorkConstraintComputationCentrewaschosenasthevenueforthe
workshop because it is a new research centre, supported by Science Foundation
Ireland and led by Eugene Freuder, which is entirely devoted to studying con-
straint processing. Thus, the workshop participants had an opportunity to see
the centre, meet its members and investigate the potential for future collabora-
tion.
Amongst the topics addressed by the papers in this volume are: verification
anddebuggingofconstraintlogicprograms;modellingandsolvingCSPs;expla-
nationgeneration;inferenceandconsistencyprocessing;SATand0/1encodings
of CSPs; soft constraints and constraint relaxation; real-world applications; and
distributed constraint solving.
I would like to acknowledge the reviewers for their assistance in evaluating
submissions for inclusion in this volume. I wish to thank the ERCIM Working
Group on Constraints, the CologNet Area for Constraint and Logic Program-
ming,andtheCorkConstraintComputationCentreforsponsoringthiseventby
coveringallthelocalexpensesandsupportingtheparticipationofseveralPh.D.
students.
January 2003 Barry O’Sullivan
Organizing Committee
Krzysztof R. Apt, CWI, The Netherlands
Franc¸ois Fages, INRIA, France
Eugene C. Freuder, University College Cork, Ireland
Barry O’Sullivan, University College Cork, Ireland
Francesca Rossi, University of Padova, Italy
Toby Walsh, University College Cork, Ireland
Additional Referees
Stefano Bistarelli Joa˜o Marques-Silva Christian Schulte
Lucas Bordeaux Ian Miguel Richard J. Wallace
James Bowen Eric Monfroy Peter Zoeteweij
Sebastian Brand Steve Prestwich
Ken Brown Patrick Prosser
Inˆes Lynce Pearl Pu
Sponsors
ERCIM Working Group on Constraints
CologNet Area for Constraint and Logic Programming
Cork Constraint Computation Centre
Table of Contents
Abstract Verification and Debugging of Constraint Logic Programs ..... 1
Manuel Hermenegildo, Germa´n Puebla, Francisco Bueno,
Pedro L´opez-Garc´ıa
CGRASS: A System for Transforming Constraint Satisfaction Problems . 15
Alan M. Frisch, Ian Miguel, Toby Walsh
Interchangeability in Soft CSPs ..................................... 31
Stefano Bistarelli, Boi Faltings, Nicoleta Neagu
Towards Automated Reasoning on the Properties of
Numerical Constraints ............................................ 47
Lucas Bordeaux, Eric Monfroy, Fr´ed´eric Benhamou
Domain-Heuristics for Arc-Consistency Algorithms .................... 62
Marc R.C. van Dongen
Computing Explanations and Implications in
Preference-Based Configurators .................................... 76
Eugene C. Freuder, Chavalit Likitvivatanavong, Manuela Moretti,
Francesca Rossi, Richard J. Wallace
Constraint Processing Offers Improved Expressiveness and
Inference for Interactive Expert Systems ............................ 93
James Bowen
A Note on Redundant Rules in Rule-Based Constraint Programming .... 109
Sebastian Brand
A Study of Encodings of Constraint Satisfaction Problems with
0/1 Variables .................................................... 121
Patrick Prosser, Evgeny Selensky
A Local Search Algorithm for Balanced Incomplete Block Designs ...... 132
Steven Prestwich
The Effect of Nogood Recording in DPLL-CBJ SAT Algorithms ........ 144
Inˆes Lynce, Joa˜o Marques-Silva
POOC – A Platform for Object-Oriented Constraint Programming ...... 159
Hans Schlenker, Georg Ringwelski
X Table of Contents
A Coordination-Based Framework for Distributed Constraint Solving.... 171
Peter Zoeteweij
Visopt ShopFloor: Going Beyond Traditional Scheduling ............... 185
Roman Bart´ak
Author Index ................................................ 201
Abstract Verification and Debugging of
Constraint Logic Programs
Manuel Hermenegildo, Germ´an Puebla, Francisco Bueno, and
Pedro Lo´pez-Garc´ıa
Department of Computer Science
Technical University of Madrid (UPM)
{herme,german,bueno,pedro}@fi.upm.es
(Extended Abstract)
Keywords: Global Analysis, Debugging, Verification, Constraint Logic Pro-
gramming, Optimization, Parallelization, Abstract Interpretation.
1 Background
The technique of Abstract Interpretation [13] has allowed the development of
sophisticated program analyses which are provably correct and practical. The
semantic approximations produced by such analyses have been traditionally ap-
plied to optimization during program compilation. However, recently, novel and
promising applications of semantic approximations have been proposed in the
more general context of program verification and debugging [3,10,7].
In the case of Constraint Logic Programs (CLP), a comparatively large
body of approximation domains, inference techniques, and tools for abstract
interpretation-based semantic analysis have been developed to a powerful and
maturelevel(see,e.g.,[28,9,21,6,22,24]andtheirreferences).Thesesystemscan
approximate at compile-time a wide range of properties, from directional types
to variable independence, determinacy or termination, always safely, and with a
significant degree of precision.
Our proposed approach takes advantage, within the context of program ver-
ification and debugging, of these significant advances in static program analysis
techniques and the resulting concrete tools, which have been shown useful for
other purposes such as optimization, and are thus likely to be present in com-
pilers. This is in contrast to using traditional proof-based methods (e.g., for the
case of CLP, [1,2,15,19,34]), developing new tools and procedures (such as spe-
cificconcrete[4,17,18]orabstract[10,11]diagnosersanddeclarativedebuggers),
or limiting error detection to run-time checking (e.g., [34]).
2 An Approach Based on Semantic Approximations
We now briefly describe the basis of our approach [7,25,31]. We consider the
important class of semantics referred to as fixpoint semantics. In this setting, a
B.O’Sullivan(Ed.):ConstraintSolvingandCLP,LNAI2627,pp.1–14,2003.
(cid:1)c Springer-VerlagBerlinHeidelberg2003