Narrow Results

We investigate formal properties, mainly issues connected with propositional logic, of reaction systems introduced by Ehrenfeucht and Rozenberg. We are concerned only with the most simple variant of the systems. Basic properties of propositional formulas are expressed in terms of reaction systems. This leads to NP-completeness (resp. co-NP-completeness) of many problems concerning reaction systems. Among such problems are: (i) deciding whether the function defined by the system is total, (ii) determining the inverse of the function, (iii) deciding whether state sequences always end with a loop. Propositional formulas with monotonic truth-functions yield a particularly simple representation in terms of reaction systems.

In this paper we present in a tutorial fashion the framework of reaction systems — a formal approach to investigating processes instigated by the living cell. The main idea behind this approach is that this functioning is determined by interactions between biochemical reactions, and these interactions are based on two mechanisms, facilitation and inhibition.