Let be a graph and be distinct vertices of . We say has a -minor or has a -minor rooted at , if there exist pairwise disjoint sets , such that for all , is connected, , and has an edge between and , where . When it is easy to determine when contains a -minor. For , Robertson, Seymour and Thomas gave a characterization of with no -minor, which, in particular, implies that such has connectivity at most 5. In this paper, we apply a method of Thomas and Wollan to prove a result, which implies that if is -connected then, for all distinct vertices of , has a -minor.

生成讲解博客的中文版本

生成AI智能校验的中文版本