Vertex capacity
= Vertex capacity
{title2=$\sum_{u}f_{uv}\leq c_v$}
An internal vertex capacity bounds the total <flow> through that vertex, equivalently its total inflow or outflow by <flow conservation>. Replace the vertex by an input and output vertex, direct incoming edges to the input and outgoing edges from the output, and connect input to output with an edge of the vertex capacity. This converts the constraint into an ordinary <flow network edge capacity>.