The upper bound for the maximal edge number of the graph has been derived, and a few valuable corollaries are also given. 给出图的最大边数的上界，并在此基础上得出了几个有用的推论。
The cyclic edge connectivity of a graph is the size of a minimum cyclic edge cutset of a graph. 一个图的圈边连通度是指最小圈边割的边数。
