A1 Refereed original research article in a scientific journal

On the Solution Sets of Three-Variable Word Equations




AuthorsSaarela, Aleksi

PublisherSPRINGER

Publishing placeNEW YORK

Publication year2024

JournalTheory of Computing Systems

Journal name in sourceTHEORY OF COMPUTING SYSTEMS

Journal acronymTHEOR COMPUT SYST

Volume68

Issue6

First page 1556

Last page1571

Number of pages16

ISSN1432-4350

eISSN1433-0490

DOIhttps://doi.org/10.1007/s00224-024-10193-9

Web address https://doi.org/10.1007/s00224-024-10193-9

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/457699339


Abstract
It is known that the set of solutions of any constant-free three-variable word equation can be represented using parametric words, and the number of numerical parameters and the level of nesting in these parametric words is at most logarithmic with respect to the length of the equation. We show that this result can be significantly improved in the case of unbalanced equations, that is, equations where at least one variable has a different number of occurrences on the left-hand side and on the right-hand side. More specifically, it is sufficient to have two numerical parameters and one level of nesting in this case. We also discuss the possibility of proving a similar result for balanced equations in the future.

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Funding information in the publication
Open Access funding provided by University of Turku (including Turku University Central Hospital).


Last updated on 2025-27-02 at 14:11