Based on the construction of a universal register machine we construct
a universal antiport P system working with 31 rules in the maximally parallel mode
in one membrane, and a universal antiport P system with forbidden context working with
16 rules in the sequential derivation mode in one membrane for computing any partial
recursive function on the set of natural numbers. For accepting/generating any arbitrary
recursively enumerable set of natural numbers we need 31/33 and 16/18 rules, respectively.
As a consequence of the result for antiport P systems with forbidden context we
immediately infer similar results for forbidden random context multiset grammars with
arbitrary rules
