Fig. 5.

Attractor of a Boolean network. (Left) A Boolean network with N = 3 nodes with possible states 0 and 1. Each node has a lookup table to determine its state given the input from other nodes. Here the two light nodes simply copy their single input, while the dark node performs the Boolean function NOR on its inputs. (Right) In the deterministic case of constant transmission delays, the system always reaches a reproducible periodic sequence of states. Filled nodes are in state 1 (on); open nodes in state 0 (off).