Another Proof of the Four Colour Theorem -- Part 2 -- Discharging a minimal 5-Chromatic Planar Graph
arXiv:2208.10936
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.
60 pages, 18 Figures, 7 Appendices, containing all exhaustive enumerations in < 500 cases. Update Sept 16: Correct typos, simplify, clarify