A FSLM network consisting of two genes and four binding sites. Left: 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, whilst gene 2 has an additional positive feedback on gene 1. Right: Result of the simulation of this network in FSLM. a1 association constantof binding site 1, d1 is the corresponding dissociation constant; a2, d2, a3, d3, a4, d4 correspondingly; ¬ Boolean „not“, & Boolean „and“. Reproduced from .