Los Angeles, CA
March 31, 2009 to April 2, 2009
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/CSIE.2009.690
A clause set is renamable Horn if the result replacing part propositional variable with its complement is a set of Horn clauses. The renamable Horn problem is solvable in linear time, but the maximum renamable Horn problem (MAX-RHS) is NP-hard. In this paper, we present transformations between clause sets and undirected graphs in polynomial time, such that finding a renamable Horn subset of a clause set is equivalent to finding an independent set of vertices of a graph. Then, the problems MAX-RHS and MAX-IND have the same complexity, and MAX-RHS is inapproximable.
maximum renamable Horn set, maximum independent set, polynomial transformation, NP-Hardness, inapproximability
Yongbin Qin, Daoyun Xu, "Maximum Renamable Horn and Maximum Independent Sets", CSIE, 2009, 2009 WRI World Congress on Computer Science and Information Engineering, CSIE, 2009 WRI World Congress on Computer Science and Information Engineering, CSIE 2009, pp. 743-747, doi:10.1109/CSIE.2009.690