Algorithm for Finding Redundant Edges in a Graph or Tree

Question

Is there an established algorithm for finding redundant edges in a graph?

For example, I\'d like to find that a->d and a->e are redundant, and then get rid of them,

Answer 1

You want to compute the smallest graph which maintains vertex reachability.

This is called the transitive reduction of a graph. The wikipedia article should get you started down the right road.