Propagation = Lazy Clause Generation

  • Olga Ohrimenko
  • Peter J. Stuckey
  • Michael Codish
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4741)

Abstract

Finite domain propagation solvers effectively represent the possible values of variables by a set of choices which can be naturally modelled as Boolean variables. In this paper we describe how we can mimic a finite domain propagation engine, by mapping propagators into clauses in a SAT solver. This immediately results in strong nogoods for finite domain propagation. But a naive static translation is impractical except in limited cases. We show how we can convert propagators to lazy clause generators for a SAT solver. The resulting system can solve scheduling problems significantly faster than generating the clauses from scratch, or using Satisfiability Modulo Theories solvers with difference logic.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Olga Ohrimenko
    • 1
  • Peter J. Stuckey
    • 1
  • Michael Codish
    • 2
  1. 1.NICTA Victoria Research Lab, Department of Comp. Sci. and Soft. Eng. University of MelbourneAustralia
  2. 2.Department of Computer Science, Ben-Gurion UniversityIsrael

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