Fig. 1
From: The phenotype control kernel of a biomolecular regulatory network
An example network and its layered network. a An example network with its update rules, where the symbols ‘&, |, !’ are used instead of the Boolean operators ‘AND, OR, NOT’, respectively. We use the symbol ‘*’ to denote the state value of a node at time t + 1. For example, the update rule A* = F denotes A(t + 1) = F(t). b We arrange nodes in the example network to locate the phenotype node P at the bottom, the 0th layer. The input nodes C and E to the node P are located just above P, which comprise the 1st layer. The input nodes B, D and F to either C or E are located just above C and E, which comprise the 2nd layer. The input node A to D is located just above D, which comprises the 3rd layer. Black arrows have directions toward the rooted node. A black arrow denotes a link pointing from a node in the (i + 1)th layer to a node in the ith layer. The other links are denoted by red dotted arrows