Local Consistency in Weighted CSPs and Inference in Max-SAT

Abstract

Weighted constraint satisfaction problems (WCSP) and Max-SAT are optimization versions of the CSP framework and SAT repectively. They have many practical applications. Most current state-of-the-art complete solvers for WCSP and Max-SAT problems can be described as a basic depth-first branch and bound search that computes a lower bound during the search that can be used together with the cost of the best solution found in order to prune entire search subtrees. Recently, a collection of local consistency properties such as NC*, AC*, DAC*, FDAC* and EDAC* have been proposed for WCSP in order to simplify the problem. In Max-SAT we have recently proposed inference rules to detect unfeasible assignments.