Nonterminal complexity of programmed grammars
نویسندگان
چکیده
منابع مشابه
Nonterminal complexity of tree controlled grammars
This paper studies the nonterminal complexity of tree controlled grammars. It is proved that the number of nonterminals in tree controlled grammars without erasing rules leads to an infinite hierarchy of families of tree controlled languages, while every recursively enumerable language can be generated by a tree controlled grammar with erasing rules and at most nine nonterminals. © 2011 Elsevie...
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A tree controlled grammar is specified as a pair (G,G) where G is a context-free grammar and G is a regular grammar. Its language consists of all terminal words with a derivation in G such that all levels of the corresponding derivation tree – except the last level – belong to L(G). We define the nonterminal complexity Var(H) of H = (G,G) as the sum of the numbers of nonterminals of G and G. In...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 2003
ISSN: 0304-3975
DOI: 10.1016/s0304-3975(02)00656-4