proposition: Lemma compA A B C D (h : A -> B) (g : B -> C) (f : C -> D) : (f \o g) \o h = f \o (g \o h).
proof: Proof. by []. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat seq eqtype choice fintype) pcm(options axioms)