Chapter 11: The Notion of Computation

Section 10: Class 4 Behavior and Universality

[Universal] totalistic rules

It is straightforward to show that totalistic cellular automata can be universal. Explicit simple candidates include k=2, r=2 rules with codes 20 and 52, as well as the various k=3, r=1 class 4 rules shown in Chapter 3.

From Stephen Wolfram: A New Kind of Science [citation]