A machine program for theorem-proving
Communications of the ACM
Integrating Equivalency Reasoning into Davis-Putnam Procedure
Proceedings of the Seventeenth National Conference on Artificial Intelligence and Twelfth Conference on Innovative Applications of Artificial Intelligence
Hidden Structure in Unsatisfiable Random 3-SAT: An Empirical Study
ICTAI '04 Proceedings of the 16th IEEE International Conference on Tools with Artificial Intelligence
Annals of Mathematics and Artificial Intelligence
Computing Horn Strong Backdoor Sets Thanks to Local Search
ICTAI '06 Proceedings of the 18th IEEE International Conference on Tools with Artificial Intelligence
Backbones and backdoors in satisfiability
AAAI'05 Proceedings of the 20th national conference on Artificial intelligence - Volume 3
Backdoors to typical case complexity
IJCAI'03 Proceedings of the 18th international joint conference on Artificial intelligence
A backbone-search heuristic for efficient solving of hard 3-SAT formulae
IJCAI'01 Proceedings of the 17th international joint conference on Artificial intelligence - Volume 1
AAAI'97/IAAI'97 Proceedings of the fourteenth national conference on artificial intelligence and ninth conference on Innovative applications of artificial intelligence
Automatic extraction of functional dependencies
SAT'04 Proceedings of the 7th international conference on Theory and Applications of Satisfiability Testing
Hi-index | 0.00 |
Identifying and exploiting hidden problem structures is recognized as a fundamental way to deal with the intractability of combinatorial problems. Recently, a particular structure called (strong) backdoor has been identified in the context of the satisfiability problem. Connections has been established between backdoors and problem hardness leading to a better approximation of the worst case time complexity. Strong backdoor sets can be computed for any tractable class. In [1], a method for the approximation of strong backdoor sets for the Horn-Sat fragment was proposed. This approximation is realized in two steps. First, the best Horn renaming of the original CNF formula, in term of number of clauses, is computed. Then a Horn strong backdoor set is extracted from the non Horn part of the renamed formula. in this article, we propose computing Horn strong backdoor sets using the same scheme but minimizing the number of positive literals in the non Horn part of the renamed formula instead of minimizing the number of non Horn clauses. Then we extend this method to the class of ordered formulas [2] which is an extension of the Horn class. This method insure to obtain ordered strong backdoor sets of size less or equal than the size of Horn strong backdoor sets (never greater). Experimental results show that these new methods allow to reduce the size of strong backdoor sets on several instances and that their exploitation also allow to enhance the efficiency of satisfiability solvers.