Journal of Automata, Languages and Combinatorics

Despite the facts that automata theory is one of the oldest and most extensively investigated areas of theoretical computer science, and finite automaton is the simplest model of computation, there are still principal open problems about finite ...

In this paper we discuss a size property of Probabilistic Cooperating Distributed Grammar Systems, grammatical constructs designed for modelling distributed random processing. We show that, with respect to the number of productions of a component ...

In this paper, the problem is revisited to what degree cooperating distributed (CD) grammar systems are more succinct than context-free grammars when describing context-free languages. The measures of descriptional complexity which are mainly considered ...

We examine the state complexity of proportional removals such as ½(L). For ½(L), we show a bound which is tight in the case that L is a unary language, and an nearly optimal bound for arbitrary languages. We also compute the average state complexity for ...

We give asymptotic estimates and some explicit computations for both the number of distinct languages and the number of distinct finite languages over a k-letter alphabet that are accepted by deterministic finite automata (resp. nondeterministic finite ...

Different modes have been considered in cooperating distributed grammar systems. Here, we consider graph-controlled grammars whose rules are applied according to one specified mode and investigate their generating power. Alternatively, these grammars ...

A binoid is an algebra which has two associative operations and the same identity to both operations. For any finite alphabet Σ, Σ^*(^, •) denotes the free binoid generated by Σ with two independent associative operations ^ and • and the identity λ. We ...

"Automata theory is not over" is the message of this paper. But if one wishes a renaissance of automata theory, then one should prefer to return to the investigation of the fundamental, classical problems of automata theory rather then searching for new ...

Multitape Turing machines with a restricted number of nondeterministic steps are investigated. Fischer and Kintala showed an infinite nondeterministic hierarchy of properly included real-time languages between the deterministic languages and the ...

We study the descriptional complexity of cellular automata (CA) which are a parallel model of computation. We show that between one of the simplest cellular models, the realtime one-way CA (realtime-OCA), and "classical" models like deterministic finite ...

In the present paper we discuss a limitation of the resources activation (productions or nonterminals) of a Chomsky grammar. We associate a possible infinite natural number with each production/nonterminal of a grammar which restricts its possibility to ...

During a derivation step, partially parallel grammars rewrite some symbols of the sentential form while leaving the others unrewritten. The present paper discusses grammars that perform two types of this parallelism - scattered rewriting and ...

In 1912, the Norwegian mathematician Axel Thue was the first to describe an overlapfree binary infinite word. This word was generated by a morphism which is called, since the works of Morse, the Thue-Morse morphism.Here we study morphisms, generalizing ...

Computing the set of descendants of a regular language L with respect to a monadic string rewriting system has proved to be very useful in developing decision algorithms for various problems on finitely presented monoids and context-free grammars. ...