Another Proof of the Four Colour Theorem -- Part 2 -- Discharging a minimal 5-Chromatic Planar Graph

Abstract

In RSST, they "replace the mammoth hand-checking of unavoidability that A&H required, by another mammoth hand-checkable proof " (page 18). Here, the proof of unavoidability is accomplished in a lengthy structured hand-checkable proof whose entirety is presented in this document.