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Comparing Complexity Functions of a Language and Its Extendable Part

Published online by Cambridge University Press:  03 June 2008

Arseny M. Shur*
Ural State University, Ekaterinburg, Russia;
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Right (left, two-sided) extendable part of a language consists of all words having infinitely many right (resp. left, two-sided) extensions within the language. We prove that for an arbitrary factorial language each of these parts has the same growth rate of complexity as the language itself. On the other hand, we exhibit a factorial language which grows superpolynomially, while its two-sided extendable part grows only linearly.


Research Article
© EDP Sciences, 2008

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