期刊名称:Electronic Colloquium on Computational Complexity
印刷版ISSN:1433-8092
出版年度:2020
卷号:2020
页码:1-29
出版社:Universität Trier, Lehrstuhl für Theoretische Computer-Forschung
摘要:We show that Cutting Planes (CP) proofs are hard to find: Given an unsatisfiable formula F, (1) it is NP-hard to find a CP refutation of F in time polynomial in the length of the shortest such refutation; and (2) unless Gap-Hitting-Set admits a nontrivial algorithm, one cannot find a tree-like CP refutation of F in time polynomial in the length of the shortest such refutation. The first result extends the recent breakthrough of Atserias and M¨uller (FOCS 2019) that established an analogous result for Resolution. Our proofs rely on two new lifting theorems: (1) Dag-like lifting for gadgets with many output bits. (2) Tree-like lifting that simulates an r-round protocol with gadgets of query complexity O(log r) independent of input length.