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arXiv 1104.1479cs.LOcs.DS
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伪布尔约束到SAT的一类编码

A Family of Encodings for Translating Pseudo-Boolean Constraints into SAT

Amir Aavani

摘要:

伪布尔(PB)约束是布尔变量上的线性算术约束。PB约束在表示NP完全问题中有着广泛的应用。我们介绍了一个新的,两个步骤,方法转换PB约束命题CNF公式。第一步涉及将每个PB约束重写为PB-Mod约束的合取。其优点是PB-Mod约束更容易转换为CNF。在第二步中,我们将上一步中获得的每个PB-Mod约束转换为CNF。所得的CNF公式很小,并且单位传播可以推导出它在通过其他常用变换获得的CNF公式中无法推导出的事实。我们还描述了约束条件,可以期望SAT求解器在所产生的CNF上表现良好。我们表明,有许多限制,建议的编码具有良好的性能。

英文摘要:

A Pseudo-Boolean (PB) constraint is a linear arithmetic constraint over Boolean variables. PB constraints are convenient and widely used in expressing NP-complete problems. We introduce a new, two step, method for transforming PB constraints to propositional CNF formulas. The first step involves re-writing each PB constraint as a conjunction of PB-Mod constraints. The advantage is that PB-Mod constraints are easier to transform to CNF. In the second step, we translate each PB-Mod constraints, obtained in the previous step, into CNF. The resulting CNF formulas are small, and unit propagation can derive facts that it cannot derive using in the CNF formulas obtained by other commonly-used transformations. We also characterize the constraints for which one can expect the SAT solvers to perform well on the produced CNF. We show that there are many constraints for which the proposed encoding has a good performance.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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