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Download fileSolutions of word equations over partially commutative structures
conference contribution
posted on 2018-02-22, 14:24 authored by Volker Diekert, Artur Jez, Manfred Kufleitner© Volker Diekert, Artur Jez, and Manfred Kufleitner. We give NSPACE(n log n) algorithms solving the following decision problems. Satisfiability: Is the given equation over a free partially commutative monoid with involution (resp. a free partially commutative group) solvable? Finiteness: Are there only finitely many solutions of such an equation? PSPACE algorithms with worse complexities for the first problem are known, but so far, a PSPACE algorithm for the second problem was out of reach. Our results are much stronger: Given such an equation, its solutions form an EDT0L language effectively representable in NSPACE(n log n). In particular, we give an effective description of the set of all solutions for equations with constraints in free partially commutative monoids and groups.
Funding
Artur Jez was supported by a return fellowship of the Alexander von Humboldt Foundation. Manfred Kufleitner was supported by the grants DI 435/5-2 and KU 2716/1-1 of the DFG.
History
School
- Science
Department
- Computer Science
Published in
43rd International Colloquium on Automata, Languages, and Programming, ICALP 2016 Leibniz International Proceedings in Informatics, LIPIcsVolume
55Citation
DIEKERT, V., JEZ, A. and KUFLEITNER, M., 2016. Solutions of word equations over partially commutative structures. Presented at the 43rd International Colloquium on Automata, Languages, and Programming (ICALP 2016), Rome, Italy, 12-15th July.Publisher
Schloss Dagstuhl – Leibniz Center for InformaticsVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/Acceptance date
2016-04-15Publication date
2016Notes
This is an Open Access Article. It is published by Schloss Dagstuhl – Leibniz Center for Informatics under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/ISBN
9783959770132ISSN
1868-8969Publisher version
Book series
Leibniz International Proceedings in Informatics, LIPIcs;55Language
- en