proposition: Lemma decides_neq (A : Type) (B : Prop) (a : A) : refine {b' | decides b' (a <> a -> B)}%comp (ret true).
proof: Proof. computes_to_econstructor; computes_to_inv; subst; simpl; auto. congruence. 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