Feasibility of Organizations–A Refinement of Chemical Organization Theory with Application to P Systems

In membrane computing, a relatively simple set of reaction rules usually implies a complex constructive dynamics, in which novel molecular species appear and present species vanish. Chemical organization theory is a new approach that deals with such systems by describing chemical computing as a transition between organizations, which are closed and self-maintaining sets of molecular species. In this paper we show that for the case of mass action kinetics some organizations are not feasible in the space of concentrations and thus need not to be considered in the analysis. We present a theorem providing criteria for an unfeasible organization. This is a refinement of organization theory making its statements more precise. In particular it follows for the design of a membrane computing system that the desired resulting organization of a chemical computing process should be a feasible organization. Nevertheless we show that due to the membranes in a P system unfeasible organizations can be observed, suggesting a strong link between the two approaches.