Figure 3.

A network consisting of two genes and four binding sites. (a) The control functions of both genes have two inputs each. One input is from a binding site for its own substance, thus each gene is autoregulated by a negative feedback loop. Gene 1 has an additional negative feedback on gene 2, while gene 2 has an additional positive feedback on gene 1. (b) Result of the simulation of this network in FSLM. a1 association constant of binding site 1, d1 is the corresponding dissociation constant; a2, d2, a3, d3, a4, d4 correspondingly; ¬ Boolean ‘not’, & Boolean ‘and’.