proposition: Lemma foreach_single : forall P X, P X -> @foreach A (set A) _ P (\{ X }).
proof: Proof. Proof using. intros_all. rewrite in_single_eq in H0. subst*. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibList LibOperation LibMonoid LibInt LibNat LibEpsilon LibRelation LibMin)