Detail publikace

Left Random Context ET0L Grammars

Originální název

Left Random Context ET0L Grammars

Anglický název

Left Random Context ET0L Grammars

Jazyk

en

Originální abstrakt

Consider ET0L grammars. Modify them such that a set of permitting symbols and a set of forbidding symbols are attached to each of their rules, just like in random context grammars. A rule like this can rewrite a symbol if each of its permitting symbols occurs to the left of the symbol to be rewritten in the current sentential form while each of its forbidding symbols does not occur there. ET0L grammars modified in this way are referred to as left random context ET0L grammars, and they represent the principal subject of the investigation in this paper. We prove that these grammars characterize the family of recursively enumerable languages, and without erasing rules, they characterize the family of context-sensitive languages. We also introduce a variety of special cases of these grammars and establish their generative power. In the conclusion, we put all the achieved results into the context of formal language theory as a whole and formulate several open questions.

Anglický abstrakt

Consider ET0L grammars. Modify them such that a set of permitting symbols and a set of forbidding symbols are attached to each of their rules, just like in random context grammars. A rule like this can rewrite a symbol if each of its permitting symbols occurs to the left of the symbol to be rewritten in the current sentential form while each of its forbidding symbols does not occur there. ET0L grammars modified in this way are referred to as left random context ET0L grammars, and they represent the principal subject of the investigation in this paper. We prove that these grammars characterize the family of recursively enumerable languages, and without erasing rules, they characterize the family of context-sensitive languages. We also introduce a variety of special cases of these grammars and establish their generative power. In the conclusion, we put all the achieved results into the context of formal language theory as a whole and formulate several open questions.

BibTex


@article{BUT103402,
  author="Alexandr {Meduna} and Petr {Zemek}",
  title="Left Random Context ET0L Grammars",
  annote="Consider ET0L grammars. Modify them such that a set of permitting symbols and
a set of forbidding symbols are attached to each of their rules, just like in
random context grammars. A rule like this can rewrite a symbol if each of its
permitting symbols occurs to the left of the symbol to be rewritten in the
current sentential form while each of its forbidding symbols does not occur
there. ET0L grammars modified in this way are referred to as left random context
ET0L grammars, and they represent the principal subject of the investigation in
this paper.

We prove that these grammars characterize the family of recursively enumerable
languages, and without erasing rules, they characterize the family of
context-sensitive languages. We also introduce a variety of special cases of
these grammars and establish their generative power. In the conclusion, we put
all the achieved results into the context of formal language theory as a whole
and formulate several open questions.",
  address="NEUVEDEN",
  chapter="103402",
  doi="10.3233/FI-2013-811",
  edition="NEUVEDEN",
  howpublished="print",
  institution="NEUVEDEN",
  number="3",
  volume="123",
  year="2013",
  month="may",
  pages="289--304",
  publisher="NEUVEDEN",
  type="journal article - other"
}