Graph splicing systems

AbstractIn this paper, extended graph splicing systems are defined. It is shown that when strings are represented as linear graphs, any recursively enumerable set can be generated by an extended graph splicing system. It is also shown that the computational completeness of extended graph splicing systems can be proved under some constraints too

On Controlled P Systems

We introduce and brie y investigate P systems with controlled computations. First, P systems with label restricted transitions are considered (in each step, all rules used have either the same label, or, possibly, the empty label, ), then P systems with the computations controlled by languages (as in context-free controlled grammars). The relationships between the families of sets of numbers computed by the various classes of controlled P systems are investigated, also comparing them with length sets of languages in Chomsky and Lindenmayer hierarchies (characterizations of the length sets of ET0L and of recursively enumerable languages are obtained in this framework). A series of open problems and research topics are formulated

P systems with picture objects

New computability models called P systems, based on the evolution of objects in a membrane structure, were recently introduced. In this paper, we consider two variants of P systems having "complex objects" like pictures as the underlying data structure. The first variant is capable of generating pictures with interesting patterns. We also investigate the generative power of this variant by comparing it with the families of two dimensional matrix languages. The second variant has some applications in pattern generation