Definition:Walk


 * Graph theory:
 * Walk: an alternating series of vertices and edges beginning and ending with a vertex in which each edge is incident with the vertex immediately preceding it and the vertex immediately following it.
 * Closed walk: a walk where the start and end vertices are the same
 * Open walk: a walk where the start and end vertices are not the same


 * Directed walk: a finite or infinite sequence $\sequence {x_k}$ of vertices such that $\forall k \in \N: k + 1 \in \Dom {\sequence {x_k} }: \tuple {x_k, x_{k + 1} } \in A$


 * Probability theory
 * Random walk