Suppose that I have already proved some theorem in coq, and later I want to introduce it as a hypothesis in the proof of another theorem. Is there a succinct way to do this?
You can use pose proof theorem_name as X., where X is the name you want to introduce.
pose proof theorem_name as X.
X
If you're going to destruct it right away, you can also: destruct (decide_eq_nat x y).
destruct (decide_eq_nat x y).