منابع مشابه
Simple Semi-conditional Et0l Grammars
The present contribution introduces and studies simple semi-conditional ET0L grammars (SSC-ET0L grammars for short). It is demonstrated that SSC-ET0L grammars with permitting and forbidding conditions of length no more than one and two, respectively, generate all the family of recursively enumerable languages; if erasing productions are not allowed, these grammars generate precisely the family ...
متن کاملA Characterization of ET0L and EDT0L Languages
There exists a PT0L language L0 such that the following holds. A language L is an ET0L language if and only if there exists a mapping T induced by an a-NGSM (nondeterministic generalized sequential machine with accepting states) such that L = T (L0). There exists an infinite collection of EPDT0L languages Dmn ⊆ Σ ⋆ mn (n ≥ m ≥ 1) such that the family EDT0L is characterized in the following way....
متن کاملOn ET0L Systems of Finite Index
The theory of L systems (see, e.g., Herman and Rozenberg (1975) and Rozenberg and Salomaa (1974, 1976)) constitutes today one of the most pursued fragments of formal language theory. Its relevance to the formal language theory stems from the facts that it introduced new range of problems and proof techniques and has put some of the old concepts and problems in a better perspective. In this pape...
متن کاملRemarks on Propagating Partition-limited Et0l Systems
In this paper, we sharpen the results of GG artner on the universality of partition-limited ET0L systems by showing that such deterministic systems characterize the recursively enumerable sets, and, furthermore, the propagating deterministic partition-limited ET0L systems characterize the programmed languages with appearance checking disallowing erasing productions. The main results of this pap...
متن کاملMembership for Limited Et0l Languages Is Not Decidable
Joseph went to register with Mary, who was promised in marriage to him. Abstract: In this paper, we show how to encode arbitrary enumerable set of numbers given by register machines within limited EPT0L systems and programmed grammars with unconditional transfer. This result has various consequences, e.g. the existence of nonre-cursive sets generable by 1lET0L systems or by programmed grammars ...
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ژورنال
عنوان ژورنال: Journal of Computer and System Sciences
سال: 1978
ISSN: 0022-0000
DOI: 10.1016/0022-0000(78)90023-5