A machine realization of the linear context-free languages

Linear Context-Free Languages Are in NC

This paper concerns linear context-free languages (LIN). We prove that LIN ⊆ NC (under UE∗−uniformity reduction). We introduce a new normal form for context-free grammars, called Dyck normal form. Using this new normal form we prove that for each context-free language L there exist an integer K and a homomorphism φ such that L = φ(D′ K), where D′ K ⊆ DK , and DK is the one-sided Dyck language o...

On minimal realization of IF-languages: A categorical approach

he purpose of this work is to introduce and study the concept of minimal deterministic automaton with IF-outputs which realizes the given IF-language. Among two methods for construction of such automaton presented here, one is based on Myhill-Nerode's theory while the other is based on derivatives of the given IF-language. Meanwhile, the categories of deterministic automata with IF-outputs and ...

Linear Time Parsers for Classes of Non Context Free Languages

Deterministic parsers have been proposed for two-level control grammars. These parsers are efficient in both time and space and are simple extensions of the standard LL(I) and LR( 1) parsers for deterministic context free languages. An important advantage of the parsers proposed here is that existing parser generator tools can be augmented to generate them from grammar specifications. Since the...

Pumping lemmas for linear and nonlinear context-free languages

Pumping lemmas are created to prove that given languages are not belong to certain language classes. There are several known pumping lemmas for the whole class and some special classes of the context-free languages. In this paper we prove new, interesting pumping lemmas for special linear and context-free language classes. Some of them can be used to pump regular languages in two place simultan...

Restarting Tree Automata and Linear Context-Free Tree Languages