Variants of Tissue P Systems with Prescribed Teams of Channel Rules
Résumé
In this paper we consider tissue P systems with prescribed teams of channel rules, with the application of the channel rules possibly depending on some given condition. A channel rule opens a channel from one cell to another one for one object to pass through it, and the channel is only open for one step. A team of channel rules then is a multiset of such channel rules. We especially investigate two variants of how the rules in the teams can be applied: in the enforcing mode, the opened channel has to be used by the object it has been opened for, whereas in the permitting mode an open channel has to be used if possible, but can also remain unused if no object exists which could pass through. We show how multiset grammars using evolution rules equipped with random context conditions can easily be simulated by teams of channel rules, as well as how variants of purely communicating (tissue) P systems can be interpreted in this framework of tissue P systems with prescribed teams of channel rules. Moreover, we prove computational completeness results for various models of purely communicating (tissue) P systems, often based on already proven results, some even with all channel rules working the enforcing mode without applicability conditions. We also show how computations on strings can be carried out by tissue P systems with prescribed teams of channel rules. Finally, we also discuss how these systems allow for “going beyond Turing”.