sQueezeBF: An Effective Preprocessor for QBFs Based on Equivalence Reasoning

  • Enrico Giunchiglia
  • Paolo Marin
  • Massimo Narizzano
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6175)


In this paper we present sQueezeBF, an effective preprocessor for QBFs that combines various techniques for eliminating variables and/or redundant clauses. In particular sQueezeBF combines (i) variable elimination via Q-resolution, (ii) variable elimination via equivalence substitution and (iii) equivalence breaking via equivalence rewriting. The experimental analysis shows that sQueezeBF can produce significant reductions in the number of clauses and/or variables - up to the point that some instances are solved directly by sQueezeBF - and that it can significantly improve the efficiency of a range of state-of-the-art QBF solvers - up to the point that some instances cannot be solved without sQueezeBF preprocessing.


Boolean Formula Propositional Formula Variable Elimination Equivalence Substitution Equivalence Breaking 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Enrico Giunchiglia
    • 1
  • Paolo Marin
    • 1
  • Massimo Narizzano
    • 1
  1. 1.DISTUniversità di GenovaGenovaItaly

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