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On Conjugacy of Languages

Published online by Cambridge University Press:  15 July 2002

Julien Cassaigne ,
Juhani Karhumäki  and
Ján Maňuch
Julien Cassaigne
Affiliation:
Institut de Mathématiques de Luminy – CNRS/FRUMAM, Case 907, 13288 Marseille Cedex 9, France; (cassaigne@iml.univ-mrs.fr)
Juhani Karhumäki
Affiliation:
Department of Mathematics and TUCS, University of Turku, 20014 Turku, Finland; (karhumak@cs.utu.fi)
Ján Maňuch
Affiliation:
TUCS and Department of Mathematics, Datacity, Lemminkäisenkatu 14A, 20520 Turku, Finland; (manuch@cs.utu.fi)
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Abstract

We say that two languages X and Y are conjugates if they satisfy the conjugacy equationXZ = ZY for some language Z. We study several problems associated with this equation. For example, we characterize all sets which are conjugated via a two-element biprefix set Z, as well as all two-element sets which are conjugates.

Keywords

Conjugacy equationlanguagesConway's Problem.
Type
Research Article
Information
RAIRO - Theoretical Informatics and Applications , Volume 35 , Issue 6: A tribute to Aldo de Luca , November 2001 , pp. 535 - 550
Copyright
© EDP Sciences, 2001

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