Quantified conjunctive queries on partially ordered sets

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14330%2F16%3A00093939" target="_blank" >RIV/00216224:14330/16:00093939 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.tcs.2016.01.010" target="_blank" >http://dx.doi.org/10.1016/j.tcs.2016.01.010</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.tcs.2016.01.010" target="_blank" >10.1016/j.tcs.2016.01.010</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantified conjunctive queries on partially ordered sets

Popis výsledku v původním jazyce

We study the computational problem of checking whether a quantified conjunctive query (a first-order sentence built using only conjunction as Boolean connective) is true in a finite poset (a reflexive, antisymmetric, and transitive directed graph). We prove that the problem is already NP-hard on a certain fixed poset, and investigate structural properties of posets yielding fixed-parameter tractability when the problem is parameterized by the query. Our main algorithmic result is that model checking quantified conjunctive queries on posets is fixed-parameter tractable when parameterized by the sentence and the width of the poset (the maximum size of a subset of pairwise incomparable elements). We complement our algorithmic result by complexity results with respect to classes of finite posets in a hierarchy of natural poset invariants, establishing its tightness in this sense. (C) 2016 Elsevier B.V. All rights reserved.

Název v anglickém jazyce

Quantified conjunctive queries on partially ordered sets

Popis výsledku anglicky

We study the computational problem of checking whether a quantified conjunctive query (a first-order sentence built using only conjunction as Boolean connective) is true in a finite poset (a reflexive, antisymmetric, and transitive directed graph). We prove that the problem is already NP-hard on a certain fixed poset, and investigate structural properties of posets yielding fixed-parameter tractability when the problem is parameterized by the query. Our main algorithmic result is that model checking quantified conjunctive queries on posets is fixed-parameter tractable when parameterized by the sentence and the width of the poset (the maximum size of a subset of pairwise incomparable elements). We complement our algorithmic result by complexity results with respect to classes of finite posets in a hierarchy of natural poset invariants, establishing its tightness in this sense. (C) 2016 Elsevier B.V. All rights reserved.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

IN - Informatika

OECD FORD obor

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Projekt

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Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Theoretical Computer Science

ISSN

0304-3975

e-ISSN

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Svazek periodika

618

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

72-84

Kód UT WoS článku

000370897800006

EID výsledku v databázi Scopus

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