VertexOutComponent

VertexOutComponent[g,{v1,v2,…}] gives the vertices in the graph g that have a directed path from at least one of v1, v2, ….

VertexOutComponent[g,{v1,v2,…},k] gives the vertices with a directed path from at least one of v1, v2, … of at most length k.

VertexOutComponent[g,{v1,v2,…},{k}] gives the vertices at length exactly k.

VertexOutComponent[{v->w,…},…] uses rules v->w to specify the graph g. 

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