一类色唯一的K_1-同胚图

令K4(i,j,k,l,m,n)表示图G的色多项式,如果P(G)=P(H),称G和H色等价;如果对任意图H,当P(H=P(G))时,都有H和G同构,称G是色唯一的.令K4(i,j,k,l,m,n)表示两两三度点间的路长分别为i,j,k,l,m,n的K4-同胚图.作者对集合{i,j,k,l,m,n}由3个不同值组成,且等于每个值的路都恰有2条的K4-同胚图的着色进行了研究,得到了1类色唯一的K4-同胚图.

A family of chromatically unique K_4 homeomorphs

Let P(G)denote the chromatic polynomial of graph G.Two graphs G and H were said to be chromatically equivalent if P(G)=P(H).A graph G was said to be chromatically unique if P(G)=P(H) implies H was isomorphic to G.Let K4(i,j,k,l,m,n) denoted the K4-homeomorph in which the lengths of its six paths between pairs of degree 3 vertices were i,j,k,l,m,n,respectively.Here,we studied the chromaticity of K4(i,j,k,l,m,n) when i,j,k,l,m,n were made up of three distinct values,and for each value there were exactly two paths whose lengths were equal to it,and obtained a family of chromatically unique K4 homeomorphs.