{"title":"Should Decisions in QCDCL Follow Prefix Order?","authors":"","doi":"10.1007/s10817-024-09694-6","DOIUrl":null,"url":null,"abstract":"<h3>Abstract</h3> <p>Quantified conflict-driven clause learning (QCDCL) is one of the main solving approaches for quantified Boolean formulas (QBF). One of the differences between QCDCL and propositional CDCL is that QCDCL typically follows the prefix order of the QBF for making decisions. We investigate an alternative model for QCDCL solving where decisions can be made in arbitrary order. The resulting system <span> <span>\\(\\textsf{QCDCL}^\\textsf {{A\\tiny {\\MakeUppercase {ny}}}}\\)</span> </span> is still sound and terminating, but does not necessarily allow to always learn asserting clauses or cubes. To address this potential drawback, we additionally introduce two subsystems that guarantee to always learn asserting clauses (<span> <span>\\(\\textsf{QCDCL}^\\textsf {{U\\tiny {\\MakeUppercase {ni}}-A\\tiny {\\MakeUppercase {ny}}}}\\)</span> </span>) and asserting cubes (<span> <span>\\(\\textsf{QCDCL}^\\textsf {{E\\tiny {\\MakeUppercase {xi}}-A\\tiny {\\MakeUppercase {ny}}}}\\)</span> </span>), respectively. We model all four approaches by formal proof systems and show that <span> <span>\\(\\textsf{QCDCL}^\\textsf {{U\\tiny {\\MakeUppercase {ni}}-A\\tiny {\\MakeUppercase {ny}}}}\\)</span> </span> is exponentially better than <span> <span>\\(\\mathsf{{QCDCL}} \\)</span> </span> on false formulas, whereas <span> <span>\\(\\textsf{QCDCL}^\\textsf {{E\\tiny {\\MakeUppercase {xi}}-A\\tiny {\\MakeUppercase {ny}}}}\\)</span> </span> is exponentially better than <span> <span>\\(\\mathsf{{QCDCL}} \\)</span> </span> on true QBFs. Technically, this involves constructing specific QBF families and showing lower and upper bounds in the respective proof systems. We complement our theoretical study with some initial experiments that confirm our theoretical findings.</p>","PeriodicalId":15082,"journal":{"name":"Journal of Automated Reasoning","volume":"80 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Automated Reasoning","FirstCategoryId":"94","ListUrlMain":"https://doi.org/10.1007/s10817-024-09694-6","RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"COMPUTER SCIENCE, ARTIFICIAL INTELLIGENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Quantified conflict-driven clause learning (QCDCL) is one of the main solving approaches for quantified Boolean formulas (QBF). One of the differences between QCDCL and propositional CDCL is that QCDCL typically follows the prefix order of the QBF for making decisions. We investigate an alternative model for QCDCL solving where decisions can be made in arbitrary order. The resulting system \(\textsf{QCDCL}^\textsf {{A\tiny {\MakeUppercase {ny}}}}\) is still sound and terminating, but does not necessarily allow to always learn asserting clauses or cubes. To address this potential drawback, we additionally introduce two subsystems that guarantee to always learn asserting clauses (\(\textsf{QCDCL}^\textsf {{U\tiny {\MakeUppercase {ni}}-A\tiny {\MakeUppercase {ny}}}}\)) and asserting cubes (\(\textsf{QCDCL}^\textsf {{E\tiny {\MakeUppercase {xi}}-A\tiny {\MakeUppercase {ny}}}}\)), respectively. We model all four approaches by formal proof systems and show that \(\textsf{QCDCL}^\textsf {{U\tiny {\MakeUppercase {ni}}-A\tiny {\MakeUppercase {ny}}}}\) is exponentially better than \(\mathsf{{QCDCL}} \) on false formulas, whereas \(\textsf{QCDCL}^\textsf {{E\tiny {\MakeUppercase {xi}}-A\tiny {\MakeUppercase {ny}}}}\) is exponentially better than \(\mathsf{{QCDCL}} \) on true QBFs. Technically, this involves constructing specific QBF families and showing lower and upper bounds in the respective proof systems. We complement our theoretical study with some initial experiments that confirm our theoretical findings.
期刊介绍:
The Journal of Automated Reasoning is an interdisciplinary journal that maintains a balance between theory, implementation and application. The spectrum of material published ranges from the presentation of a new inference rule with proof of its logical properties to a detailed account of a computer program designed to solve various problems in industry. The main fields covered are automated theorem proving, logic programming, expert systems, program synthesis and validation, artificial intelligence, computational logic, robotics, and various industrial applications. The papers share the common feature of focusing on several aspects of automated reasoning, a field whose objective is the design and implementation of a computer program that serves as an assistant in solving problems and in answering questions that require reasoning.
The Journal of Automated Reasoning provides a forum and a means for exchanging information for those interested purely in theory, those interested primarily in implementation, and those interested in specific research and industrial applications.