Sergiu Ivanov

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On the one hand, one of the concepts which lies at the basis of membrane computing is the multiset rewriting rule. On the other hand, the paradigm of rules is profusely used in computer science for representing and dealing with knowledge. Therefore , it makes much scene to establish a " bridge " between these domains, for instance, by designing P systems(More)
We consider the (one-dimensional) array counterpart of contextual as well as insertion and deletion string grammars and consider the operations of array insertion and deletion in array grammars. First we show that the emptiness problem for P systems with (one-dimensional) insertion rules is unde-cidable. Then we show computational completeness of P systems(More)
Array insertion grammars have already been considered as contextual array grammars in [5], whereas the inverse interpretation of a contextual array rule as a deletion rule has newly been introduced in [2] and [3]. The results described in this extended abstract were elaborated in [3] for one-dimensional arrays and in [2] for two-dimensional arrays.
The focus of this paper is the family of languages generated by transitional non-cooperative P systems without further ingredients. This family can also be defined by so-called time yields of derivation trees of context-free grammars. In this paper we prove that such languages can be parsed in polynomial time, where the degree of polynomial may depend on(More)
In this article we introduce the operations of insertion and deletion working in a random-context and semi-conditional manner. We show that the conditional use of rules strictly increase the computational power. In the case of semi-conditional insertion-deletion systems context-free insertion and deletion rules of one symbol are sufficient to get the(More)