Chapter 9: Fundamental Physics

Section 10: The Sequencing of Events in the Universe

Generating causal networks

If every element generated in the evolution of a generalized substitution system is assigned a unique number, then events can be represented for example by {4,5}->{11,12,13}—and from a list of such events a causal network can be built up using

With[{u = Map[First, list]}, MapIndexed[Function[{e, i}, First[i] -> ((If[# === {}, Infinity, #[[1, 1]]] &[Position[u, #]]) & /@ Last[e])], list]]

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