proposition: Lemma set_enum (A : {set T}) : [set x in enum A] = A.
proof: Proof. by apply/setP => x; rewrite inE mem_enum. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)