How to prove that each edge of tree is a bridge?
My attempt:
Tree is a connected graph which has no cycle, and in a connected graph, bridge is an edge whose removal disconnects the graph.
Let G be a tree, and each edge of G is not a bridge.
I should find a contradiction from my assumption.
But, now I can't go proceed. I think by this way I can prove, and I can't express it.
How can I go further?