Publication Details

On Tree-Restricted Regular-Controlled Context-Free Grammars

MEDUNA, A.; SOUKUP, O.; CSUHAJ-VARJÚ, E. On Tree-Restricted Regular-Controlled Context-Free Grammars. International Journal of Computer Mathematics: Computer Systems Theory, 2017, vol. 2, no. 4, p. 147-163. ISSN: 2379-9927.
Czech title
Stromová Omezení Regulárně Řízených Bezkontextových Gramatik
Type
journal article
Language
English
Authors
Meduna Alexandr, prof. RNDr., CSc. (DIFS)
Soukup Ondřej, Ing., Ph.D.
Csuhaj-Varjú Erzsébet
URL
Keywords

regular-controlled context-free grammars, restricted derivation trees, contextfreeness of finite index

Abstract

This paper gives simple tree-based conditions under which regular-controlled context-free grammars generate context-free languages of finite index, so they cannot even generate all context-free languages. It defines the notion of path-changing derivation step which corresponds to performing two consecutive rewritings of nonterminal symbols present in the different branches of the derivation tree. It proves that if there exists a certain constant that limits the number of path-changing deriva- tion steps, then, the regular-controlled grammar generates a context-free language of finite index. At the end, we generalize achieved result and provide some open problems for future study.

Published
2017
Pages
147–163
Journal
International Journal of Computer Mathematics: Computer Systems Theory, vol. 2, no. 4, ISSN 2379-9927
DOI
EID Scopus
BibTeX
@article{BUT144477,
  author="Alexandr {Meduna} and Ondřej {Soukup} and Erzsébet {Csuhaj-Varjú}",
  title="On Tree-Restricted Regular-Controlled Context-Free Grammars",
  journal="International Journal of Computer Mathematics: Computer Systems Theory",
  year="2017",
  volume="2",
  number="4",
  pages="147--163",
  doi="10.1080/23799927.2017.1388291",
  issn="2379-9927",
  url="http://dx.doi.org/10.1080/23799927.2017.1388291"
}
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