Theory and Applications of Satisfiability Testing - SAT 2009: 12th International Conference, SAT 2009, Swansea, UK, June 30 - July 3, 2009. Proceedings

552 Pages·2009·5.313 MB·English

by  Oliver Kullmann

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Oliver Kullmann (Ed.)
Theory and Applications
of Satisfiability Testing –
SAT 2009
12th International Conference, SAT 2009
Swansea, UK, June 30 - July 3, 2009
Proceedings
1 3
VolumeEditor
OliverKullmann
ComputerScienceDepartment
SwanseaUniversity
FaradayBuilding,SingletonPark
Swansea,SA28PP,UK
E-mail:[email protected]
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Preface
This volume contains the papers presented at SAT 2009: 12th International
ConferenceonTheoryandApplications ofSatisfiabilityTesting,heldfromJune
30 to July 3, 2009 in Swansea (UK).
The International Conference on Theory and Applications of Satisfiability
Testing (SAT) startedin1996asa series ofworkshops,and,in parallelwiththe
growthofSAT,developedintothemaineventforSATresearch.Thisyear’scon-
ferencetestifiedtothestronginterestinSAT,regardingtheoreticalresearch,re-
searchonalgorithms,investigationsintoapplications,anddevelopmentofsolvers
andsoftwaresystems.Asa coreproblemofcomputerscience,SAT is centralfor
many research areas, and has deep interactions with many mathematical sub-
jects. Major impulses for the development of SAT came from concrete practical
applications as well as from fundamental theoretical research. This fruitful col-
laboration can be seen in virtually all papers of this volume.
There were 86 submissions (completed papers within the scope of the con-
ference). Each submission was reviewed by at least three, and on average 4.0
Programme Committee members. The Committee decided to accept 45 papers,
consistingof34regularand11shortpapers(restrictedto6pages).Amainnov-
elty was a “shepherding process”, where 29% of the papers were accepted only
conditionally, and requirements on necessary improvements were formulated by
theProgrammeCommittee anditsinstallmentmonitoredbythe “shepherd”for
thatpaper(usingpossiblyseveralroundsoffeedback).Thisprocesshelpedenor-
mouslytoimprovethequalityofthepapers,anditalsoenabledtheProgramme
Committee to accept 13 papers, which have very interesting contributions, but
which due to weaknesses normally wouldn’t have made it into the proceedings.
27 regular and 5 short papers were accepted unconditionally, and 7 long and
7=3+4 short papers were accepted conditionally (with 4 requiredconversions
fromregulartoshortpapers).Allthese7longpapersand6ofthe7shortpapers
could then be accepted in the “secondround”, involving in all cases substantial
workfortheauthors(oftenacompleterevision)andtheshepherd(rangingfrom
providinggeneraladvicetocompletegrammaticaloverhauls).Asoneauthorput
it: “I would, however, like to congratulate the reviewers, as their review is the
most useful and thorough I have ever received from any conference - indeed, if
integrated correctly, it brings a new level of quality to the paper.”
The organisation of the papers is by subjects (and within the categories
alphabetically). The programme included two invited talks:
– Robert Niewenhuis considered how SMT (“SAT modulo theories”) can en-
hanceSATsolvinginasystematicwaybyspecialalgorithms,asitispossible
in constraint programming.
– Moshe Vardi investigated how the strong inference power delivered by OB-
DDs(“orderedbinarydecisiondiagrams”)canbeharnessedbySATsolving.
VI Preface
One of the major topics of this conference was the MAXSAT problem (max-
imising the number of satisfied clauses), and boolean optimisation problems in
general. Besides these extensions, the papers of this conference show that “core
SAT”, that is, boolean CNF-SAT solving, has still a huge potential (I expect
that we just scratched the surface, and fascinating discoveries are waiting for
us).OnefundamentaltopicwastheunderstandingofwhyandwhenSATsolvers
areefficient,andinterestingapproacheswereconsidered,towardsamoreprecise
intelligent control of the execution of SAT solvers. Another strong area of this
year was the intelligent translation of problems into SAT. Regarding QBF, the
extension of SAT by allowing quantification, the quest for a “good” problem
representationbecomes even more urgent, and we find theoretical and practical
approaches.
SeveraladditionaleventswereassociatedwiththeSAT conference,including
the SAT competition, the PB competition (“pseudo-boolean”, allowing certain
forms of arithmetic), the Max-SAT evaluation, and a special sessionon the var-
ious aspects of the process of developing SAT software.
ArnoldBeckmannandMatthew Gwynne helped with the localorganisation.
We gladly acknowledge the following people in organising the satellite events:
– themainorganisersoftheSATcompetitionDanielLeBerre,OlivierRoussel,
Laurent Simon, the judges Andreas Goerdt, Inˆes Lynce and Aaron Stump,
and the special organisers Allen Van Gelder, Armin Biere, Edmund Clarke,
John Franco and Sean Weaver
– theorganisersofthePBcompetitionVascoManquinhoandOlivierRoussel;
– and the organisers of the Max-SAT evaluation Josep Argelich, Chu Min Li,
Felip Manya` and Jordi Planes
AspecialthanksgoestotheProgrammeCommitteeandthe additionalexternal
reviewers, who through their thorough and knowledgeable work enabled the
assembly of this body of high-quality work.We also thank the authors for their
enthusiastic collaborationin further improving their papers.
The EasyChair conference management system helped us with handling of
the paper submissions, paper reviewing, paper discussion and assembly of the
proceedings.I wouldlike to thank the Chairsofthe previousyears,Hans Kleine
Bu¨ning,XishunZhaoandJoaoMarques-Silva,fortheirimportantadviceonrun-
ning a conference. The Department of Computer Science of Swansea University
providedlogisticsupport.FinallyIwouldliketothankthefollowingsponsorsfor
their support of SAT 2009: Intel Corporation, NEC Laboratories, and Invensys
Rail Group.1
April 2009 Oliver Kullmann
1 Dueto thedifficult economic circumstances a numberof former sponsors expressed
their regret for not being able to providefundingthis year.
Conference Organisation
Conference and Programme Chair
Oliver Kullmann Computer Science Department, Swansea
University, UK
Local Organisation
Arnold Beckmann Computer Science Department, Swansea
University, UK
Matthew Gwynne Computer Science Department, Swansea
University, UK
Programme Committee
Dimitris Achlioptas Daniel LeBerre Niklas So¨rensson
Armin Biere Chu Min Li Ewald Speckenmeyer
Stephen Cook Ines Lynce Stefan Szeider
Nadia Creignou Panagiotis Manolios Armando Tacchella
Evgeny Dantsin Joao Marques-Silva Miroslaw Truszczynski
Adnan Darwiche David Mitchell Alasdair Urquhart
John Franco Albert Oliveras Allen Van Gelder
Nicola Galesi Ramamohan Paturi Hans van Maaren
Enrico Giunchiglia Lakhdar Sais Toby Walsh
Ziyad Hanna Karem Sakallah Sean Weaver
Marijn Heule Uwe Sch¨oning Emo Welzl
Edward Hirsch Roberto Sebastiani Lintao Zhang
Kazuo Iwama Robert Sloan Xishun Zhao
Hans Kleine Bu¨ning Carsten Sinz
External Reviewers
Anbulagan Anbulagan Lorenzo Carlucci Anders Franzen
Carlos Anso´tegui Harsh Raju Chamarthi Heidi Gebauer
Josep Argelich Benjamin Chambers Eugene Goldberg
Regis Barbanchon Hubie Chen Alexandra Goultiaeva
Maria Luisa Bonet Gilles Dequen Alberto Griggio
Simone Bova Laure Devendeville Djamal Habet
Roberto Bruttomesso Juan Luis Esteban Shai Haim
Uwe Bubeck Paulo Flores Miki Hermann
VIII Organization
Dmitry Itsykson Robin Moser Thomas Schiex
George Katsirelos Massimo Narizzano Tatjana Schmidt
George Katsirelose Nina Naroditskaya Henning Schnoor
Arist Kojevnikov Sergey Nikolenko Yuping Shen
Stephan Kottler Sergey Nurk Michael Soltys
Alexander Kulikov Richard Ostrowski Stefano Tonetta
Javier Larrosa C´edric Piette Patrick Traxler
Silvio Lattanzi Knot Pipatsrisawat Enrico Tronci
Massimo Lauria Jordi Planes Gyorgy Turan
Jimmy Lee Stefan Porschen Olga Tveretina
Theodor Lettmann Luca Pulina Alexander Wolpert
Florian Lonsing Silvio Ranise Stefan Woltran
Toni Mancini Andreas Razen Grigory Yaroslavtsev
Vasco Manquinho Alyson Reeves Weiya Yue
Felip Manya` Olivier Roussel Bruno Zanuttini
Marco Maratea Emanuele Di Rosa Michele Zito
Paolo Marin Jabbour Said Philipp Zumstein
John Moondanos Dominik Scheder
Sponsoring Institutions
Computer Science Department, Swansea University
Invensys Rail Group
Intel Corporation
NEC Laboratories
Table of Contents
1. Invited Talks
SAT Modulo Theories: Enhancing SAT with Special-Purpose
Algorithms...................................................... 1
Robert Nieuwenhuis
Symbolic Techniques in Propositional Satisfiability Solving ............ 2
Moshe Y. Vardi
2. Applications of SAT
Efficiently Calculating Evolutionary Tree Measures Using SAT......... 4
Mar´ıa Luisa Bonet and Katherine St. John
Finding Lean Induced Cycles in Binary Hypercubes .................. 18
Yury Chebiryak, Thomas Wahl, Daniel Kroening, and Leopold Haller
Finding Efficient Circuits Using SAT-Solvers ........................ 32
Arist Kojevnikov, Alexander S. Kulikov, and Grigory Yaroslavtsev
Encoding Treewidth into SAT ..................................... 45
Marko Samer and Helmut Veith
3. Complexity Theory
The Complexity of Reasoning for Fragments of Default Logic.......... 51
Olaf Beyersdorff, Arne Meier, Michael Thomas, and
Heribert Vollmer
Does Advice Help to Prove PropositionalTautologies?................ 65
Olaf Beyersdorff and Sebastian Mu¨ller
4. Structures for SAT
Backdoors in the Context of Learning .............................. 73
Bistra Dilkina, Carla P. Gomes, and Ashish Sabharwal
Solving SAT for CNF Formulas with a One-Sided Restriction on
Variable Occurrences ............................................. 80
Daniel Johannsen, Igor Razgon, and Magnus Wahlstro¨m
On Some Aspects of Mixed Horn Formulas.......................... 86
Stefan Porschen, Tatjana Schmidt, and Ewald Speckenmeyer
X Table of Contents
Variable Influences in Conjunctive Normal Forms .................... 101
Patrick Traxler
5. Resolution and SAT
Clause-Learning Algorithms with Many Restarts and Bounded-Width
Resolution ...................................................... 114
Albert Atserias, Johannes Klaus Fichte, and Marc Thurley
An Exponential Lower Bound for Width-Restricted Clause Learning.... 128
Jan Johannsen
Improved Conflict-Clause Minimization Leads to Improved
PropositionalProof Traces ....................................... 141
Allen Van Gelder
Boundary Points and Resolution ................................... 147
Eugene Goldberg
6. Translations to CNF
Sequential Encodings from Max-CSP into Partial Max-SAT ........... 161
Josep Argelich, Alba Cabiscol, Inˆes Lynce, and Felip Manya`
Cardinality Networks and Their Applications........................ 167
Roberto As´ın, Robert Nieuwenhuis, Albert Oliveras, and
Enric Rodr´ıguez-Carbonell
New Encodings of Pseudo-BooleanConstraints into CNF ............. 181
Olivier Bailleux, Yacine Boufkhad, and Olivier Roussel
Efficient Term-ITE Conversionfor Satisfiability Modulo Theories ...... 195
Hyondeuk Kim, Fabio Somenzi, and HoonSang Jin
7. Techniques for Conflict-Driven SAT Solvers
On-the-Fly Clause Improvement ................................... 209
Hyojung Han and Fabio Somenzi
Dynamic Symmetry Breaking by Simulating Zykov Contraction........ 223
Bas Schaafsma, Marijn J.H. Heule, and Hans van Maaren
Minimizing Learned Clauses....................................... 237
Niklas So¨rensson and Armin Biere
Extending SAT Solvers to Cryptographic Problems................... 244
Mate Soos, Karsten Nohl, and Claude Castelluccia