ABSTRACT
Let u and v be vertices of a simple graph G. A path P from u to v is a sequence of vertices u0, u1, . . . , uk such that u = u0, v = uk, ui −→ ui+1, and all the ui are distinct vertices. The length of a path P is ℓ(P ), the number of edges it uses. In this example, ℓ(P ) = k, and P is called a uv-path of length k. A uv-path of length 4 is illustrated in Figure 2.1, with dashed edges.
