QingTing : A Fast SAT Solver Using Local Search and Efficient Unit Propagation

In this paper, we present a new SAT solver that combines a recently proposed local search algorithm — unitwalk — with e cient unit propagation techniques. Unlike many other local-search SAT algorithms, unitwalk ’s search relies heavily on unit propagation. In our solver, QingTing , unit propagation is implemented with an e cient unit propagation algorithm using an underlying lazy data structure. By comparing it to a more basic data structure, we empirically show how our approach is able to significantly reduce memory access in terms of clause and literal visits. Experiments also show that QingTing is up to five times faster than the original unitwalk solver on a wide range of benchmarks and competitive with other state-of-the-art SAT solvers.