Wolfram Physics Q&A

Interference occurs as a natural byproduct of the Knuth–Bendix completion procedure for multiway evolution graphs. The simplest way this can work, in the case of the double slit experiment, is as follows: in one multiway branch, the photon goes through one slit, and in another multiway branch, the photon goes through the other slit. By applying a Knuth–Bendix completion, one introduces effective lemmas that equate the divergent branch pair states between these two branches; these lemmas are sufficiently general that they allow for new states in the multiway evolution graph to be reached, and these correspond exactly to the interference states in which the photon traveled through both slits and interfered with itself.