Definition Under_rel (A : Type) (eqA : A -> A -> Prop) :=
  eqA.

(* Specifications: *)
Lemma Under_rel_from_rel : forall (A : Type) (eqA : A -> A -> Prop) (x y : A), @Under_rel A eqA x y -> eqA x y.
Lemma Under_relE (A : Type) (eqA : A -> A -> Prop) : @Under_rel A eqA = eqA.