Edge connectivity --- реберная связность.
We define the edge-connectivity, or , for the connected graph to be the size of the smallest cut-set of . is said to be -edge-connected for any positive integer satisfying . We denote the smallest degree of any vertex in a graph by . Since the set of edges incident with any vertex forms a cut-set, we have .
For any connected graph :
is the vertex-connectivity.
The local-edge-connectivity of two vertices and in a graph or digraph is the maximum number of edge-disjoint -paths in , and the edge-connectivity of is defined as .