Generalizations of this problem include the Hadwiger Conjecture, and Apollonian networks have a unique solution to this problem.
Generalizations of this problem include the Hadwiger Conjecture, and Apollonian networks have a unique solution to this problem. The 15-node Poussin graph exhibited a flaw in a supposed proof of this statement by "tangling" Kempe chains, but Heawood used Kempe's work to prove a 25% weaker bound on this problem. The proof of this conjecture required verifying (*) 1,936 separate cases. It was finally proven in 1976 by Wolfgang Haken and Kenneth Appel with the aid of a computer. For ten points, identify this mathematical problem, which states that any map with contiguous regions can be colored with less than five colors.
Generalizations of this problem include the Hadwiger Conjecture, and Apollonian networks have a unique solution to this problem.
{Four Color} Theorem