On small universal antiport P systems

It is known that P systems with antiport rules simulate register machines, i.e., they are computationally complete. Hence, due to the existence of universal register machines, there exist computationally complete subclasses of antiport P systems with bounded size, i.e., systems where each size parameter is limited by some constant. However, so far there has been no estimation of these numbers given in the literature. In this article, three universal antiport P systems of bounded size are demonstrated, different from each other in their size parameters. We present universal antiport P systems with 73, 43, and 30 rules where the maximum of the weight of the rules is 4, 5, and 6, respectively. (c) 2006 Elsevier B.V. All rights reserved.