Two Power-Decreasing Derivation Restrictions in Generalized Scattered Context Grammars

Tomáš MasopustTomáš Masopust, Alexander MedunaAlexander Meduna, Jirí SimácekJirí Simácek

ISSN: 0324-721X
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Tomáš Masopust, Alexander Meduna, Jirí Simácek
Two Power-Decreasing Derivation Restrictions in Generalized Scattered Context Grammars
Acta Cybernetica, 18(4):783-793, 2008

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KurzfassungAbstract
The present paper introduces and discusses generalized scattered context grammars that are based upon sequences of productions whose left-hand sides are formed by nonterminal strings, not just single nonterminals. It places two restrictions on the derivations in these grammars. More specifically, let k be a positive integer. The first restriction requires that all rewritten symbols occur within the first k symbols of the first continuous block of nonterminals in the sentential form during every derivation step. The other restriction defines derivations over sentential forms containing no more than k occurrences of nonterminals. As its main result, the paper demonstrates that both restrictions decrease the generative power of these grammars to the power of context-free grammars.
Forschungsgruppe:Research Group: Wissensbasierte SystemeKnowledge-Based Systems

@article{MMS2008,
  author  = {Tom{\'{a}}{\v{s}} Masopust and Alexander Meduna and Jir{\'{\i}}
             Sim{\'{a}}cek},
  title   = {Two Power-Decreasing Derivation Restrictions in Generalized
             Scattered Context Grammars},
  journal = {Acta Cybernetica},
  volume  = {18},
  number  = {4},
  year    = {2008},
  pages   = {783-793}
}