Abstract
The importance of producing a certificate of unsatisfiability is increasingly recognized for high performance propositional satisfiability solvers. The leading solvers develop a conflict graph as the basis for deriving (or “learning”) new clauses. Extracting a resolution derivation from the conflict graph is theoretically straightforward, but it turns out to have some surprising practical pitfalls (as well as the unsurprising problem that resolution proofs can be extremely long). These pitfalls are exposed, solutions are presented, and analyzed for worse cases. Dramatic improvements on industrial benchmarks are demonstrated.
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Van Gelder, A. (2007). Verifying Propositional Unsatisfiability: Pitfalls to Avoid. In: Marques-Silva, J., Sakallah, K.A. (eds) Theory and Applications of Satisfiability Testing – SAT 2007. SAT 2007. Lecture Notes in Computer Science, vol 4501. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-72788-0_31
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DOI: https://doi.org/10.1007/978-3-540-72788-0_31
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