proposition: Lemma morph_id `{tA : t A leA eqA} : morph leA eqA leA eqA (fun x : A => x).
proof: Proof. constructor. - apply PreO.morph_id. - solve_proper. Qed.
imports: SetoidClass Coq.Classes.Morphisms Coq.Arith.PeanoNat Fiat.Common.Coq__8_4__8_5__Compat