Rewriting P systems: improved hierarchies

Rewriting P Systems with Conditional Communication: Improved Hierarchies

We consider here a variant of rewriting P systems [1], where communication is controlled by the contents of the strings, not by the evolution rules used for obtaining these strings. Some new characterizations of recursively enumerable languages are obtained by means of P systems with a small number of membranes, which improves some of the known results from [1] and [4].

Parallel Array-rewriting P Systems

A variant of array-rewriting P systems that uses parallel rewriting of arrays in the regions is introduced. The generative power of this model is compared with certain array grammars generating array languages. It is shown that geometric arrays such as hollow rectangles and hollow squares can be generated by parallel array P systems with a priority relation on the rules. The advantage of the pr...

Infinite Hierarchies of Conformon-P Systems

Two models of conformon-P systems, one restricted in the number of input conformons and the other restricted in the number of input membranes, are proved to induce infinite hierarchies. The described systems do not work under the requirement of maximal parallelism and perform deterministic simulations of restricted counter machines.

Two Normal Forms for Rewriting P Systems

Rewriting in P Systems: An Algebraic Approach

We relate to the formal definition of a P system with symbol-objects, from Section 3.5 of Chapter 3 of the monograph [2]. We give an equivalent formulation of the symbol-object rewriting rules which occur in one membrane of a P system, reformulation which emphasizes the underlying algebraic structure of commutative monoid with a finite set of generators. We limit ourselves to systems with only ...