s—桥图的色惟一性

The Chromatic Uniqueness of s-aridge Graphs

由连接两个顶点的 s条内部不交的路组成的图叫 s-桥图 .记作 F (k1 ,k2 ,… ,ks) ,本文讨论了此类图的色性 ,给出了此类图色惟一的一个充分条件 .并证明了 t+2—桥图 Ft(2 ,2 ,… ,2 ,a,b)是色惟一的 .

The graph \$F(k\-1,k\-2,...,k\-s)\$ consisting of s paths joining two vertices is called a s-bridge graph.In this papes the chromaticity of the graph \$F(k\-1,k\-,...,k\-s)\$ is discussed,a sufficient condition of it being chromatically unique is obtained.And it proves a family of \$t+2 \$bridge graph \$F\-t(2,2,...,2,a,b)\$ be chromatically unique.