The 11th International Workshop on
Symmetry in Constraint Satisfaction Problems (SymCon'11)

To be held at
the 17th International Conference on the
Principles and Practice of Constraint Programming (CP'11)

Perugia, Italy
Monday 12 September 2011

The Workshop

This is the 11th 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.

Programme and Proceedings

List of accepted papers (cover sheet and preface of the proceedings):

14:00 - 14:30 Dynamic versus Static Value Symmetry Breaking (PDF)
Nina Narodytska and Toby Walsh
14:30 - 15:00 Symmetry-reinforced Nogood Recording from Restarts (PDF)
Christophe Lecoutre and Sebastien Tabary
15:00 - 15:30 Symmetry of Nonlinearity Constraints (PDF)
Venkatesh Ramamoorthy, Marius Silaghi, Toshihiro Matsui, Katsutoshi Hirayama and Makoto Yokoo
16:10 - 16:40 Exploiting Almost Symmetries with SBDS-1UIP and Conditional Symmetry Breaking Constraints (PDF)
Geoffrey Chu and Peter Stuckey
16:40 - 17:10 Breaking Variable and Value Symmetry (PDF)
Toby Walsh
17:10 - 17:40 On the Complexity of Breaking Symmetry (PDF)
Toby Walsh

Programme Committee

George Katsirelos (co-chair) LRI, France
Nina Narodytska (co-chair) UNSW and NICTA, Australia
Pierre Flener Uppsala University, Sweden
Zeynep Kiziltan University of Bologna, Italy
Christopher Mears Monash University, Australia
Justin Pearson Uppsala University, Sweden
Ashish Sabharwal IBM, USA
Lakhdar Sais CNRS, France
Pascal Van Hentenryck Brown University, USA
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'11. At least one author of each accepted paper must attend the workshop.

Important Dates

Submission deadlineJuly 1, 2011
Notification of acceptance August 10, 2011
Camera-ready copy deadlineAugust 17, 2011
WorkshopSeptember 12, 2011