\begin{definition}[Definition:Directed Walk]
Let $G = \struct {V, A}$ be a directed graph.
A '''directed walk''' in $G$ is a finite or infinite sequence $\sequence {x_k}$ such that:
:$\forall k \in \N: k + 1 \in \Dom {\sequence {x_k} }: \tuple {x_k, x_{k + 1} } \in A$
\end{definition}