The Non-Self-Embedding Property for Generalized Fuzzy Context-Free Grammars
نویسنده
چکیده
A fuzzy context-free K-grammar is a fuzzy context-free grammar with a countable rather than a finite number of rules satisfying the following condition: for each symbol α, the set containing all right-hand sides of rules with left-hand side equal to α forms a fuzzy language that belongs to a given family K of fuzzy languages. In this paper we study the effect of the non-self-embedding restriction on the generating power of fuzzy context-free K-grammars. Our main result shows that under weak assumptions on the family K, a fuzzy language is generated by a non-self-embedding fuzzy context-free K-grammar if and only if either it is a fuzzy regular language or it belongs to the substitution closure K∞ of the family K. The proof heavily relies on the closure properties of the families K and K∞.
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