Description
We will use the following (standard) definitions from graph theory. Let V be a nonempty and finite set, its elements being called vertices
(or nodes). Let E be a subset of the Cartesian product V×V, its elements being called edges. Then G=(V,E) is called a directed graph.
Let n be a positive integer, and let p=(e1,...,en) be a sequence of length n of edges ei∈E such that ei=(vi,vi+1) for a sequence of vertices(v1,...,vn+1).
Then p is called a path from vertex v1 to vertex v......
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