A causal network is an acyclic digraph arising from an evolution of a substitution system, and representing its history. The illustration above shows a causal network corresponding to the rules {B B->A, A A B->B A A B} (applied in a left-to-right scan) and initial condition A B A A B (Wolfram 2002, p. 498, fig. a). The figure above shows the procedure for diagrammatically creating a causal network from a mobile automaton.

causal invariance | multiway system