A Note on a New Class of APCol Systems

We introduce a new acceptance mode for APCol systems (Automaton-like P colonies), variants of P colonies where the environment of the agents is given by a string and during functioning the agents change their own states and process the string similarly to automata. In case of the standard variant, the string is accepted if it can be reduced to the empty word. In this paper, we de ne APCol systems where the agents verify their environment, a model resembling multihead nite automata. In this case, a string of length n is accepted if during every halting computation the length of the environmental string in the con gurations does not change and in the course of the computation every agent applies a rule to a symbol on position i of some of the environmental strings for every i, 1 < i < n at least once. We show that these verifying APCol systems simulate one-way multihead nite automata

On bounded interpretations of grammar forms

AbstractAn interpretation of a grammar form is called (k, i)-bounded iff all its nonterminals are substituted by at most k symbols and all its terminals are replaced by at most i words. The (k, i)-bounded grammar family of a grammar form is the collection of its (k, i)-bounded interpretations, and its (k, i)-bounded grammatical family is the corresponding family of languages.The paper gives basic properties of these families. Especially, we show the decidability of the equivalence problem for bounded grammar families, the undecidability of the membership problem for bounded language families and give some hierarchy, closure and descriptional complexity results. Finally, some consequences in normal form theory of context-free languages are presented

P Colony Automata with LL(k)-like Conditions

We investigate the possibility of the deterministic parsing (that is, parsing without backtracking) of languages characterized by (generalized) P colony automata. We de ne a class of P colony automata satisfying a property which resembles the LL(k) property of context-free grammars, and study the possibility of parsing the characterized languages using a k symbol lookahead, as in the LL(k) parsing method for context-free languages

Biológiai indíttatású kiszámítás: formális nyelvi modellek = Bio-inspired computation: formal language theoretic models

A biológiai indíttatású nyelvprocesszor hálózatok területén megmutattuk, hogy az elemi evolúciós processzorokból álló hibrid hálózatok a Turing gépekkel egyenlő számítási erejű eszközök. Bebizonyítottuk, hogy minden, azonos ábécé feletti rekurzíven felsorolható nyelv előállítható nem elemi evolúciós processzorok hasonló architektúrájú hibrid hálózatával. Az evolúciós processzorok kizárólagosan egy elemi genetikai művelet, azaz beszúrás, törlés vagy betűcsere elvégzésére alkalmas eszközök. A membrán rendszerek elméletében megmutattuk, hogy a P automaták, amelyek kizárólag kommunikációra épülő elfogadó membrán rendszerek, szabályaik maximálisan párhuzamos módú használata esetén a környezetfüggő nyelvek osztályát, míg a szabályaik szekvenciális módú használata esetén egy, a logaritmikusnál kisebb tárigényű nyelvosztályt határoznak meg. A P rendszerek több fontos változatáról megmutattuk, hogy a Turing gépekével egyenlő számítási erejű, még bizonyos méretparamétereinek korlátozása esetén is. A molekuláris számítástudomány területén megmutattuk a Watson-Crick komplementaritás elvére épülő ún. kiterjesztett standard Watson-Crick D0L rendszerek hálózatainak a Turing gépekével való egyenlő számítási erejét nem teljes információ közvetítésének lehetősége esetén is. | In the area of bio-inspired language processors, we proved that hibrid networks of elementary evolutionary processors are computationally complete and these networks with non-elementary components are able to determine any recursively enumerable language over the same alphabet with a similar underlying graph structure. Evolutionary processors are language determining devices capable of performing only one type of point mutations (insertion, deletion, replacement). In the theory of membrane (P) systems, we proved that P automata, i.e. accepting, purely communicating membrane systems, by applying their rules in the maximally parallel manner determine the class of context-sensitive languages and by using their rules sequentially identify a class of languages strictly included in the class of languages computable by Turing machines with a logarithmically bounded workspace. For several important variants of P systems, we proved that they are computationally complete, even if they are bounded in some of their size parameters. In the area of molecular computing, we proved that networks of extended standard Watson-Crick D0L systems, models which make use of Watson-Crick complementarity, with the possibility of incomplete information communication are computationally complete

Red-Green P Automata

In this short note we extend the notion of red-green Turing machines to speci c variants of P automata. Acceptance and recognizability of nite strings by red- green automata are de ned via in nite runs of the automaton on the input string and the way how to distinguish between red and green states