Edge-degree

Edge-degree --- рёберная степень.

The edge-degree [math]\displaystyle{ \xi_{G}(e) }[/math] of the edge [math]\displaystyle{ e =(uv) \in E(G) }[/math] is defined by

[math]\displaystyle{ \xi_{G}(e) = deg(u) + deg(v) - 2. }[/math]