Figure 1:

Wiring diagram and state space of the Boolean network $F=\left(f_1,f_2,f_3\right)=$ $\left(x_2\wedge \neg x_3,x_3,\neg x_1\wedge x_2\right)$. (a) The wiring diagram encodes the dependency between variables. Subnetworks are defined on the basis of the wiring diagram. For example, the subnetwork ${\left.F\right|}_{\left\{x_2,x_3\right\}}\left(x_1,x_2,x_3\right)=\left(x_3,\neg x_1\wedge x_2\right)$ is the restriction of $F$ to $\left\{x_2,x_3\right\}$ and contains external parameter $x_1$. (b) The state space is a directed graph with edges between all states and their images. This graph therefore encodes all possible trajectories and attractors. Here, $F$ has two steady states, 000 and 011, and one limit cycle, (010,101), so $𝒜\left(F\right)=\{\mathrm{000,011},(\mathrm{010,101}\left)\right\}$.