One and Two Polarizations, Membrane Creation and Objects Complexity in P Systems

We improve, by using register machines, some existing universality results for specific models of P systems. P systems with membrane creation are known to generate all recursively enumerable sets of vectors of non-negative integers, even when no region (except the environment) contains more than one object of the same kind. We here show that they generate all recursively enumerable languages, and two membrane labels are sufficient (the same result holds for accepting all recursively enumerable vectors of non-negative integers). Moreover, at most two objects are present inside the system at any time in the generative case. Then we prove that 10 + m symbols are enough to generate any recursively enumerable language over m symbols. P systems with active membranes without polarizations are known to generate all recursively enumerable sets of vectors of non-negative integers. We show that they generate all recursively enumerable languages; four starting membranes with three labels or sev...

• Type: Conference
• Year: 2005
• Where: SYNASC
• Authors: Artiom Alhazov, Rudolf Freund, Agustin Riscos-Núñez
• Keywords: Enumerable, Non-negative Integers, Recursively Enumerable Languages, SYNASC 2005