Evolution-communication P systems

We propose a new class of P systems that use simple evolution rules (classical evolution rules without communication targets) and symport/antiport rules (for communication). This type of P system is realistic for (at least) three different reasons: we do not have target indications in the evolution rules, we use very simple symport/antiport rules to realize communication, and we do not need objects available in the environment at the beginning of a computation. Somewhat expected, this new variant is still universal. We prove the universality in two cases: when using catalytic rules (but only one catalyst), symport/antiport rules of weight one, and two membranes, and when we use three membranes, symport/antiport rules of weight one, and no catalyst. Especially the latter result is of interest, because the catalysts were used in most universality proofs for P systems with symbol-objects. Also new is the proof technique we use: we start from programmed grammars with unconditional transfer. © Springer-Verlag Berlin Heidelberg 2003.