Alica Kelemenová

A grammar-theoretic treatment of multiagent systems

A variant of cooperating and distributed grammar systems—the so-called colony—is studied to capture some aspects of multiagent systems consisting of a finite number of very simple autonomous agents. A colony is considered as a set up from a finite number of regular grammars generating finite languages that cooperate without any explicit predefined strategy. Generative power and hierarchical properties of colonies are investigated. The behavioral (generative) stability of colonies as well as a modified model augmenting agents by ‘clocks’ is studied. It is proved that the generative power of colonies with augmented components overcomes the generative power of colonies without clocks.

Languages of colonies

Abstract A colony is a finite set of regular grammars, where each grammar generates a finite language. The component grammars cooperate to derive a common language. In this paper we compare the generative power of colonies with two cooperation strategies and with several types of the selection of the alphabet for the common language. The results give representations of languages of colonies in terms of classes of sequential and parallel languages.

Complexity of normal form grammars

Abstract Various types of grammars can be used to describe context-free languages. Such are context-free grammars and their normal form restrictions. Rewriting of a context-free grammar to an equivalent grammar in required (normal) form can cause a change of parameters of the grammar such as the number of rules, the number of nonterminals, etc. Greibach normal form grammars and position restricted grammars will be investigated from the point of view of descriptional complexity of context-free languages.

Trends, Techniques, and Problems in Theoretical Computer Science

Lower bound techniques for VLSI algorithms.- The equivalence of mappings on languages.- Kleenes theorem revisited.- Some combinatorial problems concerning finite languages.- A connection between descriptional complexity of context-free grammars and grammar form theory.- Basic ideas of selective substitution grammars.- Some recent restrictions in the derivation of context-free grammars.- Recent results on the theory of homogeneous structures.- A note on the ratio function in DOL systems.- Models for multicellular development: Characterization, inference and complexity of L-systems.- A formal model of knowledge-based systems.- Basic complexity analysis of hypothesis formation.- Perspectives of logic programming.

Descriptional complexity of context-free grammar forms

Csuhaj-Vajh, E. and A. Kelemenovi, Descriptional complexity of context-free grammar forms, Theoretical Computer Science 112 (1993) 277-289. Descriptional complexity aspects of grammar forms are studied. It is shown that grammatical complexity measures HEI,q, LEV,<, VAR,<, PROD,< and DEP., related to any appropriate infinite class ‘8 of grammars are unbounded on the infinite class of languages determined by strict/general interpretations of any infinite grammar form.

Grammatical Levels of the Position Restricted Grammars

Structural complexity of context-free languages is studied for the description of context-free languages by position restricted grammars.

A0L-and CFG- Size of Languages

For a given language the size of minimal underlying AOL systems and the size of minimal underlying CF grammars are compared.

Regeneration on IL systems

Abstract We study the minimum size of context needed to regenerate a fixed word by a propagating DIL system without using extra symbols. It is proven that the size of context depends on the maximum length of subwords occuring in two different positions in the fixed word.

Size of context in regenerative IL systems

We determine the minimum size of context needed to regenerate a word from any of its nonempty subword. For a given word w, the context (k,1) is sufficient for PDIL systems over alph(w), where k is the maximum length of subwords occurring in two different positions in w.