SATsolve

SATsolve is a software tool for solving Boolean satisfiability problems, focusing on formulas expressed in conjunctive normal form. It accepts inputs in standard formats such as DIMACS CNF and returns either a satisfying assignment for the variables or a proof that the formula is unsatisfiable.

The solver implements modern techniques used in contemporary SAT solvers. Core components include conflict-driven clause learning (CDCL), activity-based variable selection (often using VSIDS or similar heuristics), restarts, and clause learning. Preprocessing and in-processing steps simplify formulas before or during solving, using methods such as variable elimination, subsumption, and blocked clause elimination. The combination of these techniques enables efficient traversal of the search space for many hard instances.

SATsolve offers features commonly used in research and practice, such as incremental solving, unsatisfiable core extraction, and generation of certificates or proofs of unsatisfiability. It is designed as a modular system with a clear interface between the parsing front end, the solver core, and optional back-end tools. The project is distributed as open-source software and provides documentation and example benchmarks for users and developers.

In practice, SATsolve is applied in areas including hardware and software verification, formal methods, constraint solving, and AI planning. It has been evaluated on standard benchmark suites and is reported to be competitive with other state-of-the-art solvers in several classes of problems.