Book ChapterDOI
End-Marked maximal depth-first contextual grammars
K. Lakshmanan
- pp 339-350
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It is shown that the three basic non-context-free constructions in natural languages can be realized upon using these variants and the family of languages generated by end-marked maximal depth-first grammars contains non-semilinear languages.Abstract:
In this paper, we present a few results which are of interest for the potential application of contextual grammars to natural languages We introduce two new classes of internal contextual grammars, called end-marked maximal depth-first and inner end-marked maximal depth-first contextual grammars We analyze the new variants with respect to the basic properties of the mildly context sensitive languages With this aim, we show that (i) the three basic non-context-free constructions in natural languages can be realized upon using these variants, (ii) the membership problem for these family of languages is decidable in polynomial time algorithm, (iii) the family of languages generated by end-marked maximal depth-first grammars contains non-semilinear languages We also solve the following open problem addressed in [3] and [1]: whether the families of languages generated by maximal depth-first and maximal local contextual grammars are semilinear or not?read more
Citations
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Journal Article
Semi-bracketed contextual grammars
TL;DR: A new class of fully bracketed contextual grammars is introduced, called the semi-bracketed contextual Grammars, where the selectors can also be non-minimally Dyck covered language and the tree structure to the derived strings is still preserved in this variant.
Book ChapterDOI
On the Relative Expressive Power of Contextual Grammars with Maximal and Depth-First Derivations
TL;DR: It is proved an interesting result that all these families of contextual languages are incomparable to each other, but they are not disjoint.
References
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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.
Proceedings ArticleDOI
Contextual grammars
TL;DR: Every finite sequence of elements in ia called a vocnbuV is said to be a s t r i n g o n V, which is a finite set of strings on the vocabulary V~ and let@be a finite se@ of contexts on V.
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 some classes of contextual grammars
TL;DR: A restricted version of depth-first contextual grammars, which depends on length of the inserting contexts, is considered, which gives a solution to the open problem P14 listed in [8].