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In this paper, tabu search for SAT is investigated from an experimental point of view. To this end, TSAT, a basic tabu search algorithm for SAT, is introduced and compared with Selman et al. Random Walk Strategy GSAT procedure, in short RWS-GSAT. TSAT does not involve the additional stochastic process of RWS-GSAT. This should facilitate the understanding of(More)
In this paper, a new pre-processing step is proposed in the resolution of SAT instances, that recovers and exploits structural knowledge that is hidden in the CNF. It delivers an hybrid formula made of clauses together with a set of equations of the form y = f (x1,. .. , xn) where f is a standard connective operator among (∨, ∧, ⇔) and where y and xi are(More)
In this paper, a new complete technique to compute Maximal Satisfiable Subsets (MSS) and Minimally Unsatisfiable Subformulas (MUS) of sets of Boolean clauses is introduced. The approach improves the currently most efficient complete technique in several ways. It makes use of the powerful concept of critical clause and of a compu-tationally inexpensive local(More)
In this paper, a new complete technique to compute Maximal Satisfiable Subsets (MSSes) and Minimally Unsatisfiable Subformulas (MUSes) of sets of Boolean clauses is introduced. The approach improves the currently most efficient complete technique in several ways. It makes use of the powerful concept of critical clause and of a computationally inexpensive(More)
In this paper, we propose a new dynamic management policy of the learnt clause database in modern SAT solvers. It is based on a dynamic freezing and activation principle of the learnt clauses. At a given search state, using a relevant selection function, it activates the most promising learnt clauses while freezing irrelevant ones. In this way, clauses(More)
In this paper, we investigate to which extent the elimination of a class of redundant clauses in SAT instances could improve the efficiency of modern satisfiability provers. Since testing whether a SAT instance does not contain any redundant clause is NP-complete, a logically incomplete but polynomial-time procedure to remove redundant clauses is proposed(More)
In this paper, an efficient heuristic allowing one to localize inconsistent kernels in propositional knowledge‐bases is described. Then, it is shown that local search techniques can boost the performance of logically complete methods for SAT. More precisely, local search techniques can be used to guide the branching strategy of logically complete techniques(More)