Introducing Intel(R) SAT Solver

We introduce Intel(R) SAT Solver (IntelSAT) - a new open-source CDCL SAT solver, written from scratch. IntelSAT is optimized for applications which generate many mostly satisfiable incremental SAT queries. We apply the following Incremental Lazy Backtracking (ILB) principle: in-between incremental queries, backtrack only when necessary and to the highest possible decision level. ILB is enabled by a novel reimplication procedure, which can reimply an assigned literal at a lower level without backtracking. Reimplication also helped us to restore the following two properties, lost in the modern solvers with the introduction of chronological backtracking: no assigned literal can be implied at a lower level, conflict analysis always starts with a clause falsified at the lowest possible level. In addition, we apply some new heuristics. Integrating IntelSAT into the MaxSAT solver TT-Open-WBO-Inc resulted in a significant performance boost on incomplete unweighted MaxSAT Evaluation benchmarks and improved the state-of-the-art in anytime unweighted MaxSAT solving