Proof complexity for the maximum satisfiability problem and its use in SAT refutations

MaxSAT, the optimization version of the well-known SAT problem, has attracted a lot of research interest in the past decade. Motivated by the many important applications and inspired by the success of modern SAT solvers, researchers have developed many MaxSAT solvers. Since most research is algorith...

Full description

Bibliographic Details
Authors: Rollón Rico, Emma|||0000-0001-8021-9464, Larrosa Bondia, Francisco Javier|||0000-0002-8322-0505
Format: article
Publication Date:2022
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/389909
Online Access:https://hdl.handle.net/2117/389909
https://dx.doi.org/10.1093/logcom/exac004
Access Level:Open access
Keyword:Computer logic
Algorithms
SAT problem
MaxSAT solvers
Proof complexity
SAT refutations
Lògica informàtica
Algorismes
Àrees temàtiques de la UPC::Informàtica::Informàtica teòrica
Description
Summary:MaxSAT, the optimization version of the well-known SAT problem, has attracted a lot of research interest in the past decade. Motivated by the many important applications and inspired by the success of modern SAT solvers, researchers have developed many MaxSAT solvers. Since most research is algorithmic, its significance is mostly evaluated empirically. In this paper, we want to address MaxSAT from the more formal point of view of proof complexity. With that aim, we start providing basic definitions and proving some basic results. Then we analyse the effect of adding split and virtual, two original inference rules, to MaxSAT resolution. We show that each addition makes the resulting proof system stronger, even when virtual is restricted to empty clauses (0-virtual). We also analyse the power of our proof systems in the particular case of SAT refutations. We show that our strongest system, ResSV, is equivalent to circular and dual rail with split. We also analyse empirically some known gadget-based reformulations. Our results seem to indicate that the advantage of these three seemingly different systems over general resolution comes mainly from their ability of augmenting the original formula with hypothetical inconsistencies, as captured in a very simple way by the virtual rule.