A1 Refereed original research article in a scientific journal

Language equations with complementation: Expressive power




AuthorsOkhotin A, Yakimova O

PublisherELSEVIER SCIENCE BV

Publication year2012

JournalTheoretical Computer Science

Journal name in sourceTHEORETICAL COMPUTER SCIENCE

Journal acronymTHEOR COMPUT SCI

Volume416

First page 71

Last page86

Number of pages16

ISSN0304-3975

DOIhttps://doi.org/10.1016/j.tcs.2011.10.003(external)


Abstract
Consider a system of language equations of the form X-i = phi(i)(X-1,...,X-n)(1 <= i <= n), where every phi(i) may contain the operations of concatenation and complementation. These systems have been studied in "Language equations with complementation: Decision problems" [A. Okhotin, O. Yakimova, Theoretical Computer Science 376 (2007) 112-126]. This paper investigates the family of languages representable by unique solutions of such systems. A method for proving nonrepresentability of particular languages is developed. Several natural subfamilies of this family are compared to each other and to the main known families of formal languages. Their position in the hierarchy is established. (C) 2011 Elsevier B.V. All rights reserved.



Last updated on 2024-26-11 at 12:08