Definition surj_set_quo :
  forall (E : Setoid) (R : Relation E) (p : equivalence R),
  MAP E (quotient E R p).

(* Specifications: *)
Lemma surj_set_quo_surjective : forall (E : Setoid) (R : Relation E) (p : equivalence R), surjective (surj_set_quo E R p).