English

A counterexample for the polar conjecture of Spencer-Brown

Combinatorics 2026-07-24 v1 Geometric Topology

Abstract

In 1976, George Spencer-Brown announced a proof of the four color theorem, using operations on Tait colorings for trivalent plane graphs. In subsequent work he formulated these operations in terms of an algorithm that he called a parity-pass and claimed that when the parity pass algorithm is performed on a non-polar pentagon region, it necessarily terminates in an edge coloring that is extendable to the entire graph. We provide here a counterexample to show that this claim is false. We then raise questions related to the existence of this sort of counterexample.

Keywords

Cite

@article{arxiv.2607.22398,
  title  = {A counterexample for the polar conjecture of Spencer-Brown},
  author = {Scott Baldridge and Louis H. Kauffman and Ben McCarty},
  journal= {arXiv preprint arXiv:2607.22398},
  year   = {2026}
}

Comments

14 pages, multiple figures