On Representing Biological Systems through Multiset Rewriting

We model qualitative and quantitative aspects of metabolic pathways by using a stochastic version of Multiset Rewriting (SMSR). They offer a natural way of describing both the static and the dynamic aspects of metabolic pathways. We argue that, due to its simple conceptual model, SMSR may be conveniently used as an intermediate language where many higher level specification languages may be compiled (e.g., as in the security protocol example). As a first step, we show also how SMSR may be used to simulate Stochastic Petri Nets for describing metabolic pathways.