【摘要】 混合超图是含有两种超边的超图,一种称为D-超边,一种称为C-超边,它们的区别主要体现在着色要求上.在任一着色中,要求每一D-超边至少有两个点着不同的颜色,每一C-超边至少有两个点着相同的颜色.只含D-超边的超图称为D-超图,只含C-超边的超图称为C-超图.主要讨论了C-超图的完美性问题,给出了完美C-超图的一个充分条件。更多还原

【Abstract】 The notion of mixed hypergraph was introduced by Vitaly Voloshin, it is a generalization of the notion of hypergraphs. The lower and upper chromatic numbers of a mixed hypergraph are both important. A mixed hypergraph is called a C-hypergraphs if it contains C-edges only. The perfectness of C-hypergraphs is discussed and a sufficient condition for a C-perfect C-hypergraph isgiven.更多还原