Results 201 to 210 of about 550 (233)
Some of the next articles are maybe not open access.
International Journal of Computer Mathematics, 1997
The family of recursively enumerable languages is characterized by scattered context grammars with four nonterminals. Moreover, this family is characterized by scattered context grammars with three nonterminals if these grammars start their derivations from a word rather than a symbol.
Alexander Meduna
exaly +2 more sources
The family of recursively enumerable languages is characterized by scattered context grammars with four nonterminals. Moreover, this family is characterized by scattered context grammars with three nonterminals if these grammars start their derivations from a word rather than a symbol.
Alexander Meduna
exaly +2 more sources
PC grammar systems with five context-free components generate all recursively enumerable languages [PDF]
Theoretical Computer Science, 2003 Parallel communicating grammar systems (PC grammar systems, in short) are language generating devices consisting of several context-free grammars which work synchronously on their own sentential forms and communicate the generated strings to each other ...
György Vaszil
exaly +2 more sources
On characterizations of recursively enumerable languages
Acta Informatica, 1990\textit{V. Geffert} [Theor. Comput. Sci. 62, 235-249 (1988; Zbl 0664.68075)] has shown that each recursively enumerable language L over \(\Sigma\) can be expressed in the form \(L=\{h(x)^{-1}g(x)|\) x in \(\Delta^+\}\cap \Sigma^*\) where \(\Delta\) is an alphabet and g, h is a pair of morphisms.
Michel Latteux, Paavo Turakainen
openaire +2 more sources
Flow languages equal recursively enumerable languages
Acta Informatica, 1981Recently, A.C. Shaw introduced a new class of expressions called flow expressions, and conjectured that the formal descriptive power of flow expressions lies somewhat below context-sensitive grammers. In this paper, we give a negative answer for his conjecture, that is, we show that all recursively enumerable languages may be denoted by flow ...
Toshiro Araki, Nobuki Tokura
openaire +2 more sources
Closure properties for fuzzy recursively enumerable languages and fuzzy recursive languages
Journal of Intelligent & Fuzzy Systems, 2016There are several variations of fuzzy Turing machines in the literature, many of them require a t-norm in order to establish their accepted language. This paper generalize the concept of non-deterministic fuzzy Turing machine - NTFM, replacing the t-norm operator for several aggregation functions.
Antonio Diego Silva Farias +3 more
openaire +1 more source
Global Syntax and Semantics for Recursively Enumerable Languages
Fundamenta Informaticae, 1981According to (Benson, 1970), a syntax is a category of strings and derivations (modulo similarity) between them. In this paper the semantic domain is an elementary topes. Thus, an interpretation of a syntax is a cofunctor taking strigs to products and derivations to morphisms.
Cristian Calude, Gheorghe Paun
openaire +2 more sources
On Conservative Learning of Recursively Enumerable Languages
2013Conservative partial learning is a variant of partial learning whereby the learner, on a text for a target language L, outputs one index e with L = W e infinitely often and every further hypothesis d is output only finitely often and satisfies \(L \not\subseteq W_d\).
Ziyuan Gao +2 more
openaire +1 more source
Grammar systems as language analyzers and recursively enumerable languages
1999We consider parallel communicating grammar systems which consist of several grammars and perform derivation steps, where each of the grammars works in a parallel and synchronized manner on its own sentential form, and communication steps, where a transfer of sentential forms is done.
Henning Bordihn +2 more
openaire +1 more source