Paths sequences connected vertices from "summary" of Introduction to Graph Theory by Douglas Brent West
A path in a graph is a sequence of distinct vertices in which consecutive vertices are adjacent. For example, in the graph G = (V, E), a path from vertex u to vertex v is a finite sequence of distinct vertices v0, v1, v2, ..., vk such that v0 = u, vk = v, and each vi is adjacent to vi+1 for i = 0, 1, 2, ..., k - 1. The length of a path is the number of edges in the path, which is one less than the number of vertices.
A sequence of vertices {v0, v1, v2, ..., vk} is a path if and only if {vi, vi+1} is an edge for i = 0, 1, 2, ..., k - 1. The vertices v0 and vk are the endpoints of the path. If the graph is directed, then the edges {vi, vi+1} must be directed edges with vi as the tail and vi+1 as the head.
Two vertices u and v are connected if there is a path from u to v. In other words, there is a sequence of vertices ...
