Neighbor-Dependent Substitution Systems of Two Kinds

A substitution system of two kinds that is neighbor dependent assigns any combination up to two kinds (in this case, two colors), with assignments based on both the state of the cell being substituted and its rightmost neighbor.

There are a total of 7^{4}=2401 rules for a neighbor-dependent substitution system of two kinds.

The neighbor-dependent substitution system of two kinds is described on pages 84–85 of S. Wolfram, A New Kind of Science, Champaign, IL: Wolfram Media Inc., 2002.