Indegree, in-degree

Indegree, in-degree --- полустепень захода вершины.

The indegree of the vertex [math]\displaystyle{ v }[/math] in a digraph [math]\displaystyle{ G }[/math] is the number of distinct arcs with the target [math]\displaystyle{ v }[/math] and is denoted by [math]\displaystyle{ in(v,G) }[/math].