On deterministic indexed languages
نویسندگان
چکیده
منابع مشابه
Deterministic Fuzzy Automaton on Subclasses of Fuzzy Regular ω-Languages
In formal language theory, we are mainly interested in the natural language computational aspects of ω-languages. Therefore in this respect it is convenient to consider fuzzy ω-languages. In this paper, we introduce two subclasses of fuzzy regular ω-languages called fuzzy n-local ω-languages and Buchi fuzzy n-local ω-languages, and give some closure properties for those subclasses. We define a ...
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We characterize the infinite words determined by indexed languages. An infinite language L determines an infinite word α if every string in L is a prefix of α. If L is regular or context-free, it is known that α must be ultimately periodic. We show that if L is an indexed language, then α is a morphic word, i.e., α can be generated by iterating a morphism under a coding. Since the other directi...
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ions. A fruitful idea in the analysis of complex systems is that of abstractions: Instead of working with the original model, one considers a model that has a simpler structure but preserves pertinent properties. A prominent example of such an abstraction is the Parikh image, which is available whenever the semantics of a model is given as a formal language. If L is a language over an alphabet ...
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T h e occu rren ce o f purely syn tactica l cross-serial depen den cies in S w iss-G erm an show s that con text-free gram m ars can n ot describe the string sets o f natu ral lan guage [Shi85]. T h e least class in the C h om sk y hierarchy th at can d escribe u n lim ited cross-serial depen dencies is in dexed g ram m ars [A h o 68]. G azd a r discuss in [G a z88] the ap p licab ility o f in...
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A regular language is k-lookahead deterministic (resp. k-block deterministic) if it is specified by a k-lookahead deterministic (resp. k-block deterministic) regular expression. These two subclasses of regular languages have been respectively introduced by Han and Wood (k-lookahead determinism) and by Giammarresi et al. (k-block determinism) as a possible extension of one-unambiguous languages ...
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ژورنال
عنوان ژورنال: Information and Control
سال: 1980
ISSN: 0019-9958
DOI: 10.1016/s0019-9958(80)90867-0