摘要
本文首先推广了可到达顶点的概念,然后引进了V的子集的闭集和闭包的定义.最后得到一些有趣的性质和结果。
In this paper we first extend the concept of reachable points, then intr-oduce the definitions of closed set and colsure which are subsets of V. Finallywe obtain some interesting properties and results related to these definitionsand concept.
关键词
简单有向图
闭集
跨出集
闭包
closed set
stride set
closure
only stride point
