# Why does a graph traversal algorithm is initialised with visited[s]←true

I just had a course on algorithm, we just started to study graph traversal. the teacher wrote analgorithm but I think there is a mistake: I'm a bit shy so I didn't asked her why so...

EXPLORE (s:sommet, D:dictionnary of the following vertexes or ahed of vertexes,
var visited:tab)
var: LIST:list; i,j: vertexes;
visited[s]←_true_;
LIST←{s}
While LISTE ≠ 0
Select i∈LIST
if ∃ j ∈ D[i], not visited[j]
visited[j]←true;
Else LISTE←LISTE-{i}


visited[s]←_true_;


What does that mean? shouldn't it be false? At the begining, we haven't visited any vertexes yet?

visited[j]←true;

visited[j]←true; LIST←LIST+{j};