Michael Codish

Senior Academic

Propagation = Lazy clause generation

Olga Ohrimenko, Peter J. Stuckey, Michael Codish

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.

Publication language English
Pages 544-558
Publication status Published - 01.01.2007

ASJC Scopus subject areas

Theoretical Computer Science
General Computer Science