Variable and Clause Ordering in an FSA Approach to Propositional Satisfiability

  • José M. Castaño
  • Rodrigo Castaño
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6807)


We use a finite state (FSA) construction approach to address the problem of propositional satisfiability (SAT). We use a very simple translation from formulas in conjunctive normal form (CNF) to regular expressions and use regular expressions to construct an FSA. As a consequence of the FSA construction, we obtain an ALL-SAT solver and model counter. We compare how several variable ordering (state ordering) heuristics affect the running time of the FSA construction. We also present a strategy for clause ordering (automata composition). We compare the running time of state-of-the-art model counters, BDD based sat solvers and we show that this FSA approach obtains state-of-the-art performance on some hard unsatisfiable benchmarks. This work brings up many questions on the possible use of automata to address SAT.


ALL-SAT model counting FSA intersection regular expression compilation 


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© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • José M. Castaño
    • 1
  • Rodrigo Castaño
    • 1
  1. 1.Depto. de ComputaciónFCEyN, UBAArgentina

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