منابع مشابه
Reflection in the Chomsky Hierarchy
The class of regular languages can be generated from the regular expressions. These regular expressions, however, do not themselves form a regular language, as can be seen using the pumping lemma. On the other hand, the class of enumerable languages can be enumerated by a universal language that is one of its elements. We say that the enumerable languages are reflexive. In this paper we investi...
متن کاملSplicing systems and the Chomsky hierarchy
In this paper, we prove decidability properties and new results on the position of the family of languages generated by (circular) splicing systems within the Chomsky hierarchy. The two main results of the paper are the following. First, we show that it is decidable, given a circular splicing language and a regular language, whether they are equal. Second, we prove the language generated by an ...
متن کاملNatural Languages And The Chomsky Hierarchy
The central claim of the paper is that NL stringsets are regular. Three independent arguments are offered in favor of this position: one based on parsimony considerations, one employing the McCullogh-Pitts (1943) model of neurons, and a purely linguistic one. It is possible to derive explicit upper bounds for the number of (live) states in NL acceptors: the results show that finite state NL par...
متن کاملAn Insertion into the Chomsky Hierarchy?
This review paper will report on some recent discoveries in the area of Formal Languages, chie y by F. Otto, G. Buntrock and G. Niemann. These discoveries have pointed out certain break-throughs connected with the concept of growing contextsensitive languages, which originated in the 1980's with a paper by E. Dahlhaus and M.K. Warmuth. One important result is that the deterministic growing cont...
متن کاملTowards a Coalgebraic Chomsky Hierarchy
The Chomsky hierarchy plays a prominent role in the foundations of theoretical computer science relating classes of formal languages of primary importance as well as the grammars and machine models that represent those language classes. It is well-known that regular languages can be captured by coalgebras. They form precisely the image of all finite coalgebras for the set functor X 7→ 2×X under...
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ژورنال
عنوان ژورنال: Theory of Computing Systems
سال: 2007
ISSN: 1432-4350,1433-0490
DOI: 10.1007/s00224-007-2017-8