1. Path:
Path is sequence of edges such that the Terminal vertex of some edge Ei is the Initial vertex of some edge Ej appearing next in the sequence, where 1<=i, J<=n
Path is sequence of edges such that the Terminal vertex of some edge Ei is the Initial vertex of some edge Ej appearing next in the sequence, where 1<=i, J<=n
2.Reachability:
A vertex v of a digraph is said to be reachable from vertex u if there is a directed path in that digraph from u to v
A vertex v of a digraph is said to be reachable from vertex u if there is a directed path in that digraph from u to v
