【摘要】 Hadwiger提出如下猜想:若G是k色图,则包含子式Kk,其中k=5时等价于四色定理.本文给出了5色图的一个必要条件,即5色图包含子式K5-.更多还原

【Abstract】 Hadwiger conjectured that a k-colourable graph contains minor K-k.The conjecture is equvalent to the four color theorem when k=5.In this paper,we obtain a simple proof of the following result: a 5-colourable graph contain a minor K~--5.This also possibly provided a solution to the proof of the four color theorem other than using the computer.更多还原