Summary: Multiple Preprocessing for Systematic SAT Solvers
, John Slaney1,2
Logic and Computation Program, National ICT Australia Ltd.
Computer Sciences Laboratory, Australian National University
High-performance SAT solvers based on systematic search generally use either
conflict driven clause learning (CDCL) or lookahead techniques to gain efficiency.
Both styles of reasoning can gain from a preprocessing phase in which some form
of deduction is used to simplify the problem. In this paper we undertake an empir-
ical examination of the effects of several recently proposed preprocessors on both
CDCL and lookahead-based SAT solvers. One finding is that the use of multiple
preprocessors one after the other can be much more effective than using any one of
them alone, but that the order in which they are applied is significant. We intend
our results to be particularly useful to those implementing new preprocessors and