论图的坚韧度（Ⅰ）──基本理论

On the Toughness of a Graph(Ⅰ)

本文首先指出坚韧度τ（Ｇ）是可以用来刻划图的连通性，因而能广泛地应用于通讯网络可靠性等有关领域的研究。进而，研究了坚韧度的自身特性，诸如取值范围、存在性问题、计数问题以及计算问题等。

In this paper,it is proved that τ (G) can be sued to describe the connectivity of a graph.The properties of the toughness of a graph, such as the range of value,enumeration,computing, Are studied.