proposition: Lemma refine_if_bool_eta : forall (u : bool), refine (if u then (ret true) else (ret false)) (ret u).
proof: Proof. destruct u; reflexivity. Qed.
imports: Coq.Strings.String Coq.Sets.Ensembles Coq.Bool.Bool Fiat.Common Fiat.Common.BoolFacts Fiat.Common.LogicFacts Fiat.Computation.Core Fiat.Computation.Monad Fiat.Computation.SetoidMorphisms Fiat.Computation.Refinements.Tactics