SAT graph-based representation: A new perspective
Journal of Algorithms
Backdoors in the Context of Learning
SAT '09 Proceedings of the 12th International Conference on Theory and Applications of Satisfiability Testing
Tradeoffs in the complexity of backdoor detection
CP'07 Proceedings of the 13th international conference on Principles and practice of constraint programming
From horn strong backdoor sets to ordered strong backdoor sets
MICAI'07 Proceedings of the artificial intelligence 6th Mexican international conference on Advances in artificial intelligence
Computation of renameable Horn backdoors
SAT'08 Proceedings of the 11th international conference on Theory and applications of satisfiability testing
Finding small backdoors in SAT instances
Canadian AI'11 Proceedings of the 24th Canadian conference on Advances in artificial intelligence
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In this paper a new approach for computing Strong Backdoor sets of boolean formula in conjunctive normal form (CNF) is proposed. It makes an original use of local search techniques for finding an assignment leading to a largest renamable Horn sub-formula of a given CNF. More precisely, at each step, preference is given to variables such that when assigned to the opposite value lead to the smallest number of remaining non- Horn clauses. Consequently, if no positive or non Horn clauses remain in the formula, our approach answer the satisfiability of the original formula; otherwise, a smallest non-Horn sub-formula is used to extract the set of variables (Strong Backdoor) such that when assigned leads to a tractable sub-formula. Branching on the variables of the Strong Backdoor set leads to significant improvements of Zchaff SAT solver with respect to many real worlds SAT instances.