Chapter 11: The Notion of Computation

Section 6: Emulating Cellular Automata with Other Systems

Computations with register machines

As an example, the following program for a 3-register machine starting with initial condition {n, 0, 0} will compute {Round[Sqrt[n]], 0, 0}:

{d[1,4], i[1], d[1,15], i[2], d[1,6], d[1,11], i[1], d[2,7], d[3,7], d[1,15], d[3,4], i[3], d[2,12], d[3,4]}

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