منابع مشابه
Context-Free Languages via Coalgebraic Trace Semantics
In this paper we identify context-free grammars as coalgebras. To obtain the associated context-free languages (consisting of only finite-length strings) we introduce a general and novel technique of finite trace semantics for coalgebras. It builds on top of the (possibly infinite) trace semantics introduced earlier by the second author, but extracts only finite behavior. Interestingly the fini...
متن کاملSyntactic Complexity of Star-Free Languages
The syntactic complexity of a regular language is the cardinality of its syntactic semigroup. The syntactic complexity of a subclass of regular languages is the maximal syntactic complexity of languages in that subclass, taken as a function of the state complexity of these languages. We study the syntactic complexity of star-free regular languages, that is, languages that can be constructed fro...
متن کاملStar-free languages are Church-Rosser congruential
The class of Church-Rosser congruential languages has been introduced by McNaughton, Narendran, and Otto in 1988. A language L is Church-Rosser congruential (belongs to CRCL), if there is a finite, confluent, and length-reducing semi-Thue system S such that L is a finite union of congruence classes modulo S. To date, it is still open whether every regular language is in CRCL. In this paper, we ...
متن کاملStar-Free Geodesic Languages for Groups
In this article we show that every group with a finite presentation satisfying one or both of the small cancellation conditions C(1/6) and C(1/4)− T (4) has the property that the set of all geodesics (over the same generating set) is a star-free regular language. Star-free regularity of the geodesic set is shown to be dependent on the generating set chosen, even for free groups. We also show th...
متن کاملQuotient Complexity of Star-Free Languages
The quotient complexity, also known as state complexity, of a regular language is the number of distinct left quotients of the language. The quotient complexity of an operation is the maximal quotient complexity of the language resulting from the operation, as a function of the quotient complexities of the operands. The class of star-free languages is the smallest class containing the finite la...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 1992
ISSN: 0304-3975
DOI: 10.1016/0304-3975(92)90080-y