Show simple item record

dc.contributor.authorArratia Quesada, Argimiro Alejandro
dc.contributor.authorOrtiz Gómez, Carlos
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament de Llenguatges i Sistemes Informàtics
dc.identifier.citationArratia, A.; Ortiz, C. Syntactic approximations to computational complexity classes. A: Conference on Computability in Europe. "Computation and Logic in the Real World, Third Conference on Computability in Europe (CiE 2007)". Siena: 2007, p. 1-15.
dc.description.abstractWe present a formal syntax of approximate formulas suited for the logic with counting quantifiers SOLP. This logic was studied by us in [1] where, among other properties, we showed: (i) In the presence of a built–in (linear) order, SOLP can describe NP–complete problems and fragments of it capture classes like P and NL; (ii) weakening the ordering relation to an almost order we can separate meaningful fragments, using a combinatorial tool adapted to these languages. The purpose of the approximate formulas presented here, is to provide a syntactic approximation to logics contained in SOLP with built-in order, that should be complementary of the semantic approximation based on almost orders, by producing approximating logics where problems are described within a small counting error. We state and prove a Bridge Theorem that links expressibility in fragments of SOLP over almostordered structures to expressibility with respect to approximate formulas for the corresponding fragments over ordered structures. A consequence of these results is that proving inexpressibility results over fragments of SOLP with built-in order could be done by proving inexpressibility over the corresponding fragments with built-in almost order, where separation proofs are allegedly easier.
dc.format.extent15 p.
dc.rightsAttribution-NonCommercial-NoDerivs 3.0 Spain
dc.subjectÀrees temàtiques de la UPC::Informàtica::Informàtica teòrica::Algorísmica i teoria de la complexitat
dc.subject.lcshComputer logic
dc.subject.lcshComputational complexity
dc.titleSyntactic approximations to computational complexity classes
dc.typeConference report
dc.subject.lemacLògica informàtica
dc.subject.lemacComplexitat computacional
dc.contributor.groupUniversitat Politècnica de Catalunya. LARCA - Laboratori d'Algorísmia Relacional, Complexitat i Aprenentatge
dc.description.peerreviewedPeer Reviewed
dc.rights.accessOpen Access
dc.description.versionPostprint (published version)
upcommons.citation.authorArratia, A.; Ortiz, C.
upcommons.citation.contributorConference on Computability in Europe
upcommons.citation.publicationNameComputation and Logic in the Real World, Third Conference on Computability in Europe (CiE 2007)

Files in this item


This item appears in the following Collection(s)

Show simple item record

Except where otherwise noted, content on this work is licensed under a Creative Commons license: Attribution-NonCommercial-NoDerivs 3.0 Spain