The 12th International Workshop on
Symmetry in Constraint Satisfaction Problems (SymCon'12)

To be held at
the 18th International Conference on the
Principles and Practice of Constraint Programming (CP'12)

Quebec City, Canada
Monday 8 October 2012

The Workshop

This is the 12th workshop of the very successful SymCon series, founded in 2001. It will be a half-day workshop open to anyone interested in the topic. The event will have a strong workshop flavour, with ample time allocated to discussion.

This year workshop presentations cover the most important developments in symmetry in SAT, CP and beyond in the last 2 years.


9:05 - 9:15 Introduction
Nina Narodytska
Session 1 (Symmetry in SAT)
9:15 - 9:37 Exploiting Symmetry in Structure-Aware SAT Solvers (Abstract)
Ashish Sabharwal
9:38 - 10:00 Symmetry Propagation: Improved Dynamic Symmetry Breaking in SAT (Abstract)
Chris Mears
10:00 - 10:30 Coffee break
Session 2 (Symmetry in CP and Beyond)
10:30 - 10:52 Extending Lazy Clause Generation to Dynamically break Symmetries and Almost Symmetries (Abstract)
Maria Garcia de la Banda
10:52 - 11:14 Beyond Lex Leader: Breaking Symmetry with Other Orderings (Abstract)
Toby Walsh
11:14 - 11:36 Increasing Symmetry Breaking by Eliminating Eliminated Symmetries: Case Studies (Abstract)
Samirror Lee
11:36 - 11:58 Variable Symmetry Breaking in Numeric Constraint Problems (Abstract)
Christophe Jermann
11:58 - 12:20 Symmetries in graph monomorphism problems (Abstract)
Philippe Vismara

Programme Committee

Nina Narodytska (chair) UNSW and NICTA, Australia
Pierre Flener Uppsala University, Sweden
Marijn Heule University of Texas at Austin, USA
Christopher Jefferson University of St. Andrews, UK
George Katsirelos INRA, France
Zeynep Kiziltan University of Bologna, Italy
Jimmy Lee The Chinese University of Hong Kong, Hong Kong
Christopher Mears Monash University, Australia
Justin Pearson Uppsala University, Sweden
Karen Petrie University of Dundee, UK
Lakhdar Sais CNRS, France
Pascal Van Hentenryck University of Melbourne and NICTA, Australia
Toby Walsh UNSW and NICTA, Australia


A symmetry is a transformation that preserves solutions that are considered equivalent. For instance, rotating a chess board 180 degrees gives a board that is indistinguishable from the original board. Symmetry increases the apparent complexity of combinatorial problems. In the presence of symmetry, a constraint solver may waste a large amount of time considering symmetric but equivalent assignments or partial assignments. Hence, dealing with symmetry is often crucial to the success of solving such combinatorial problems efficiently.

Workshop topics include (but are not limited to):


Submissions must be formatted in the Lecture Notes in Computer Science (LNCS) style and must not exceed 15 pages. Submissions of shorter papers, including position papers, are welcome. Papers must be submitted in PDF format using EasyChair.

All submissions will be reviewed and those that are well written and make a worthwhile contribution to the topic of the workshop will be accepted for publication in the workshop proceedings. The proceedings will be available electronically at CP'12. At least one author of each accepted paper must attend the workshop. Please note that every workshop participant needs to be registered for the workshop.

Important Dates

Submission deadline Friday 20 July 2012
Notification of acceptance Tuesday 14 August 2012
Camera-ready copy deadlineMonday 27 August 2012
WorkshopMonday 8 October 2012