Definition Equalizer_law1 := Equalizer_eq e.

(* Specifications: *)
Lemma E_monic : Monic_law (E_mor f).
Lemma Epic_Equalizer_id : Epic_law (E_mor f) -> Equalizer_eq (Id a).
Lemma Epic_Equalizer_iso : forall p : Epic_law (E_mor f), let f1 := E_diese f (Epic_Equalizer_id p) in AreIsos (E_mor f) f1.