Clarity required on graph related concepts

[ChPravin]

hi all
when talking in term of trees/graphs:
1)what is meant by pre-processing an edge and pre-processing a vertex?(The context in which this is mentioned is Depth First Search)
2)What is the definition of a depth first spanning forest?
3)What are the requirements for a vertex to be an articulation point?(in terms of back edges)
Also can someone suggest a good resource where articulation points are explained clearly?

thanks and regards

[hwwong]

Hi,
1)Can you be more specific? Pre-processing can mean anything.
2) The forest generated by DFS traversal such that edges in forests are the forward edges in DFS.
3) I think the following link can help you.
http://www.student.cs.uwaterloo.ca/~cs3 ... Unit17.pdf

Cheers,

[ChPravin]

thanks for the replies