一类色唯一的K_4同胚图

Chromatic Uniqueness of a Family of K_4Homeomorphs

本文证得 :如果正整数x ,y,z ,u ,v ,w中有四个数等于a(≥ 2 ) ,而另外两个数均小于a或其中一个大于a、另一个小于a ,则k4 (x ,y ,z ,u ,v ,w)是色唯一的。

The K 4 Homeomorphs is denoted by k 4(x,y,z,u,v,w),in which the lengths of its six paths between pairs of degree-3 vertices are x,y,z,u,v,w,respectively We study the chromatic uniqueness of one family of K 4 Homeomorphs This family has exactly 4 paths of legth a(≥2).The results of this study lead us to solve remained cases in[3].