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Sequential Precede Chain for Value Symmetry Elimination

  • Graeme GangeEmail author
  • Peter J. Stuckey
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11008)

Abstract

The main global constraint used for removing value symmetries is the value-precede-chain constraint which forces the first occurences of values in an ordered list to be appear in order. We introduce the seq-precede-chain constraint for the restricted, but common, case where the values are \(1,2, \ldots , k\), and variables in the constraint do not take values higher than k. We construct an efficient domain consistent propagator for this constraint, and show how we can generate explanations for its propagation. This leads us to an efficient domain consistent decomposition. We show how we can map any value-precede-chain to use instead seq-precede-chain. Experiments show that the new propagator and decomposition are better than existing approachs to propagating value-precede-chain.

Notes

Acknowledgements

This research is supported by the Australian Research Council through grant DE160100568 and the Asian Office of Aerospace Research and Development grant 15-4016.

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Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Faculty of Information TechnologyMonash UniversityMelbourneAustralia
  2. 2.Data61, CSIROMelbourneAustralia

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