Walk

Walk --- маршрут.

An alternating sequence of not necessarily distinct vertices and edges, starting and ending with a vertex, in which every edge is incident with two vertices immediately preceding and following it. If all vertices of a walk are distinct (and hence also all edges in the walk are distinct), the walk is called a simple chain or sometimes a path. The walk [math]\displaystyle{ (x_{1}, \ldots, x_{k+1}) }[/math] is open [ closed] iff [math]\displaystyle{ x_{k+1} \neq x_{1} }[/math] [[math]\displaystyle{ x_{k+1} = x_{1} }[/math]]. The length of the walk is [math]\displaystyle{ k }[/math] above. A walk is a trail, if no edge is used twice.

The other name is Sequence.