Let Q be the set of all primitive words over a finite alphabet having at least two letters. In this paper, we study the language D(1) of all non-overlapping (d-primitive) words, which is a proper subset of Q. We show that D(1) is a contextsensitive langauage but not a deterministic context-free language. Further it is shown that [D(1)]n is not regular for n ≥ 1. key words: primitive word, non-o...

In this paper, we investigate various concepts of leftmost derivation in grammars controlled by bicoloured digraphs, especially regarding their descriptive capacity. This approach allows us to unify the presentation of known results regarding especially programmed grammars and matrix grammars, and to obtain new results concerning grammars with regular control, and periodically time-variant gram...

Statistical methods have turned out to be quite successful in natural language processing. During the recent years, several models of stochastic grammars have been proposed, including models based on lexicalised context-free grammars [3], tree adjoining grammars [15], or dependency grammars [2, 5]. In this exploratory paper, we propose a new model of stochastic grammar, whose originality derive...

Motivated by aspects of robustness in parsing a context-free language, we study generalized fuzzy context-free grammars. These fuzzy context-free K-grammars provide a general framework to describe correctly as well as erroneously derived sentences by a single generating mechanism. They model the situation of making a finite choice out of an infinity of possible grammatical errors during each co...

Pregroup grammars are a context-free grammar formalism which may be used to describe the syntax of natural languages. However, this formalism is not able to naturally define types corresponding to optional and iterated arguments such as optional complements of verbs or verbs’ adverbial modifiers. This paper introduces two constructions that make up for this deficiency.

We study parsing of tree adjoining grammars with particular emphasis on the use of shared forests to represent all the parse trees deriving a well-formed string. We show that there are two distinct ways of representing the parse forest one of which involves the use of linear indexed grammars and the other the use of context-free grammars. The work presented in this paper is intended to give a g...

Generalized Multitext Grammar (GMTG) is a synchronous grammar formalism that is weakly equivalent to Linear Context-free Rewriting Systems (LCFRS), but retains much of the notational and intuitive simplicity of Context-Free Grammar (CFG). GMTG allows both synchronous and independent rewriting. Such flexibility facilitates more perspicuous modeling of parallel text than what is possible with oth...

Linguistic resources are very important to any natural language processing task. Unfortunately, the manual construction of these resources is laborious and time-consuming. The use of annotated corpora as a knowledge database might be a solution to a fast construction of a grammar for a given language. In this paper, we present our method to automatically induce a syntactic grammar from an Arabi...

In the past years there have been many attempts to fill in the gap between the classes of LL(k) and LR(k) grammars with new classes of deterministically parsable grammars. Almost always the introduction of a new class was accompanied by a parsing method and/or a grammatical transformation fitting the following scheme. If parsers were at the centre of the investigation the new method used to be ...