Figure 1

A simple GRN and its state graph. A: A simple GRN. The network contains three entities, A, B and C. Entities A and C regulate entity B, B regulates C, and C regulates A. Each table shows the level of the regulated gene when its regulation function acts, depending on the regulators' levels. B: The state graph of the GRN. Nodes correspond to global states (with coordinates A, B, C from left to right), and edges to transitions between these states. The labels on the edges show the regulation functions that cause this transition. C: The restricted state graph starting from the initial state 000. Only states that are reachable by transitions from 000 are shown. For simplicity, self loops are not shown. Sequences of state traversals that follow from the initial state can be cyclic (return to the same state) or can lead to the endpoint state 111.