Regular Languages Are Church-Rosser Congruential
نویسندگان
چکیده
منابع مشابه
Star-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 ...
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In this paper the concept of Parikh-reducing Church-Rosser systems is studied. It is shown that for two classes of regular languages there exist such systems which describe the languages using finitely many equivalence classes of the rewriting system. The two classes are: 1.) the class of all regular languages such that the syntactic monoid contains only abelian groups and 2.) the class of all ...
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ژورنال
عنوان ژورنال: Journal of the ACM
سال: 2015
ISSN: 0004-5411,1557-735X
DOI: 10.1145/2808227