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The optimism about the possibilities of DNA computing is based on two central issues: the Watson-Crick complementarity and the massive parallelism of DNA strands. While the latter issue renders exhaustive searches possible and thus may settle problems previously considered intractable, the former issue is the cause behind the universality of many models of… (More)
The paper considers the simplest class of parallel communicating grammar systems, namely with regular components, which yet seems to be not enough investigated. It is proved that in the centralized returning case (deriving in the usual mode) and in the non-centralized non-returning case with terminal derivation the systems are not "too powerful", more… (More)
The so-called replication operation is studied in the case when several insertion contexts consisting of letters are used, as well as in the case when this operation is applied to several strings. Some striking diierences, depending on the technical details of the setup, are observed in the generative power of this operation.
We consider the following new way of generating a language: start with a string w and a given set of insertion contexts (u; v); if uv appears as a substring of w, then we can insert in between u and v any substring of w which starts with v and ends with u (hence preserving the link restriction encoded by (u; v)); iterating this operation, we get a language.… (More)
Subclasses of grammar systems that can facilitate parser construction appear to be of interest. In this paper, some syntactical conditions considered for strict deterministic grammars are extended to cooperating distributed grammar systems, restricted to the terminal derivation mode. Two variants are considered according to the level to which the conditions… (More)
We associate Szilard and extended Szilard languages to parallel communicating grammar systems, starting from labels associated to productions of the components of the systems. We study families of such languages associated to various classes of parallel communicating grammar systems, comparing them to each other, to families of languages generated by… (More)