Abstract
We introduce a definition of constraint symmetry for soft CSPs, based on the definition of constraint symmetry for classical CSPs. We show that the constraint symmetry group of a soft CSP is a subgroup of that of an associated classical CSP instance. Where it is smaller, we can successfully exploit the additional symmetries using conditional symmetry breaking. We demonstrate, in a case-study of graph colouring, that eliminating the symmetry of the soft CSP combined with conditional symmetry breaking can lead to huge reductions in the search effort to find an optimal solution to the soft CSP.
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Bistarelli, S.: Semirings for Soft Constraint Solving and Programming. LNCS, vol. 2962. Springer, Heidelberg (2004)
Bistarelli, S., Kelleher, J., O’Sullivan, B.: Symmetry Breaking in Soft CSPs. In: Proceedings of AI 2003, BCS Conference Series, pp. 199–212. Springer, Heidelberg (2004)
Bistarelli, S., Montanari, U., Rossi, F.: Semiring-based constraint solving and optimization. Journal of ACM 44(2), 201–236 (1997)
Bistarelli, S., O’Sullivan, B.: Combining branch & bound and SBDD to solve soft CSPs. In: Proceedings of SymCon Workshop (2004)
Cohen, D., Jeavons, P., Jefferson, C., Petrie, K.E., Smith, B.M.: Symmetry Definitions for Constraint Programming. Constraints 11, 115–137 (2006)
Gent, I.P., Kelsey, T., Linton, S.A., McDonald, I., Miguel, I., Smith, B.M.: Conditional Symmetry Breaking. In: van Beek, P. (ed.) CP 2005. LNCS, vol. 3709, pp. 256–270. Springer, Heidelberg (2005)
Gent, I.P., Smith, B.M.: Symmetry Breaking During Search in Constraint Programming. In: Horn, W. (ed.) Proceedings ECAI 2000, pp. 599–603 (2000)
Meseguer, P., Rossi, F., Schiex, T.: Soft constraints. In: Rossi, F., van Beek, P., Walsh, T. (eds.) Handbook of Constraint Programming, vol. 9, pp. 281–328. Elsevier, Amsterdam (2006)
Smith, B.M., Bistarelli, S., O’Sullivan, B.: Constraint Symmetry for the Soft CSP. Technical Report CPPod-22-2007, CPPod Research Group (2007), Available from http://www.dcs.st-and.ac.uk/~cppod/publications/reports/cppod-22-2007.pdf
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Smith, B.M., Bistarelli, S., O’Sullivan, B. (2007). Constraint Symmetry for the Soft CSP. In: Bessière, C. (eds) Principles and Practice of Constraint Programming – CP 2007. CP 2007. Lecture Notes in Computer Science, vol 4741. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-74970-7_66
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DOI: https://doi.org/10.1007/978-3-540-74970-7_66
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-74969-1
Online ISBN: 978-3-540-74970-7
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