Look-Ahead Evolution for P Systems

Abstract

Summary. This article introduces a new derivation mode for P systems that permits to make a look-ahead on the next configuration and check for some forbidding conditions on it. The interesting point is that the software implementation of this mode needs very small modifications to the standard algorithm of rule assignment for maximally parallelism. As benefits of this mode some non-deterministic proofs become deterministic. As an example we present a generalized communicating P system that accepts 2 n in n steps in a deterministic way. Another example shows that in the deterministic case this mode is more powerful than the maximally parallel derivation mode. Finally, this mode gives a natural way to define P systems that may accept or reject a computation.