On Variants of Communicating Distributed H Systems

A recent result shows that a variant of communicating distributed H system with two components can generate recursive enumerable languages. In this variant the filters are a finite union of sets whose number depends upon the simulated system. We prove here that it is possible to obtain the same result using filters testing the presence of couples of symbols. The number of the couples does not depend upon the simulated systems. Moreover we investigate variants of communicating distributed H systems with limitations in the redistribution process.