On the Efficiency of P Systems with Active Membranes and Two Polarizations

We present an algorithm for deterministically deciding SAT in linear time by P systems with active membranes using only two polarizations and rules of types (a), (c), and (e). Moreover, various restrictions on the general form of the rules are considered: global, non-renaming, independent of the polarization, preserving it, changing it, producing two membranes with different polarizations, having exactly one or two objects in (each membrane of) the right-hand side, thus improving results from [1]. Several problems related to different combinations of these restrictions are formulated, too.