Backdoor Sets for DLL Subsolvers
Backdoor Sets for DLL Subsolvers
复制标题
DOI:
10.1007/s10817-005-9007-9
复制
发表时间:
2005-10
期刊:
影响因子:
--
通讯作者:
Stefan Szeider
中科院分区:
文献类型:
--
作者:
Stefan Szeider
We study the parameterized complexity of detecting smallbackdoor setsfor instances of the propositional satisfiability problem (SAT). The notion of backdoor sets has been recently introduced by Williams, Gomes, and Selman for explaining the ‘heavy-tailed’ behavior of backtracking algorithms. If a small backdoor set is found, then the instance can be solved efficiently by the propagation and simplification mechanisms of a SAT solver. Empirical studies indicate that structured SAT instances coming from practical applications have small backdoor sets. We study the worst-case complexity of detecting backdoor sets with respect to the simplification and propagation mechanisms of the classic Davis–Logemann–Loveland (DLL) procedure. We show that the detection of backdoor sets of size bounded by a fixed integerkis of high parameterized complexity. In particular, we determine that this detection problem (and some of its variants) is complete for the parameterized complexity class W[P]. We achieve this result by means of a generalization of a reduction due to Abrahamson, Downey, and Fellows.