An exact algorithm for the constraint satisfaction problem: Application to logical inference

The inference problem in propositional logic realizes a strong connection between Artificial Intelligence and Operational Research. It is now well-known that this problem can be formulated as a constraint satisfaction problem (CSP), whose system has a generalized covering type (we recall that a CSP consists in proving the emptiness of a domain defined by a set of diophantine constraints, or the existence of a solution). We propose a new method - denoted by FAST (Fast Algorithm for the constraint Satisfaction Test problems) - which allows an efficient solution of the CSP instances for logical inference. Computational results are reported for 3-SAT, 4-SAT and system expert type instances.