Journal ArticleDOI
Contextual grammars: parallelism and blocking of derivation
TLDR
This work considers contextual grammars with parallel derivations, in which the whole current string participates to a derivation step in the sense that it is splitted into substrings to which contexts are adjoined in a parallel manner.Abstract:
Continuing the work begun in [14], we consider contextual grammars (as introduced in [6] with linguistic motivation) with parallel derivations, in which the whole current string participates to a derivation step in the sense that it is splitted into substrings to which contexts are adjoined in a parallel manner. The generative power of such grammars is investigated, when the parallelism is total or partial, and when the selection of contexts is limited to strings in sets of a given type (finite, regular etc.) Then we consider the languages consisting of strings which cannot be further derived (we call them blocking languages). Some open problems are also formulated.read more
Citations
More filters
Book ChapterDOI
Contextual grammars and formal languages
TL;DR: The chapter by S. Marcus in this handbook gives a lucid account of the motivation behind contextual grammars from the natural point of view.
Journal ArticleDOI
On computational complexity of contextual languages
TL;DR: It is shown that all the three basic non-context-free constructions in natural languages, that is, multiple agreements, crossed agreements, and duplication, can be realized using this type of grammars and that these languages are parsable in polynomial time.
Journal ArticleDOI
On representing recursively enumerable languages by internal contextual languages
TL;DR: It is proved that each recursively enumerable language L can be written in the form L = cut c ( L 0 ∩ R ), where L 0 is an internal contextual language, R is a regular language, and cut c is the operation which for a word x removes the prefix of x to the left of the unique occurrence of ± in x .
Journal ArticleDOI
Structured Contextual Grammars
Carlos Martín-Vide,Gheorghe Paun +1 more
TL;DR: First, the idea of associating a tree to a derivation in such a grammar is considered, which can be done in a natural way, by associating parentheses to the contexts of the grammar, which obtains a restriction on the derivations in a contextual grammar, as well as a direct manner of defining the ambiguity of contextual grammars.
Journal ArticleDOI
Parallel Grammars: A Phenomenology
Henning Fernau,Henning Fernau +1 more
TL;DR: The aim of this paper is to give prospective PhD students in the area hints at where to start a promising research; and to supplement earlier reference lists on parallel grammars, trying to cover recent papers as well as ``older'' papers which were somehow neglected in other reviews.
References
More filters
Book
Marcus Contextual Grammars
Gheorghe Paun,Gheorghe Pun +1 more
TL;DR: 1. Origin and Motivation, Formal Language Theory Prerequisites, and A Generalization: n-Contextual Grammars.
Journal Article