auto with algebra.
Qed.

(* Specifications: *)
Lemma Ker_prop_rev :
forall x : Mod, Equal (f x) (monoid_unit Mod2) -> in_part x Ker.
Lemma coKer_prop : forall x : Mod, in_part (f x) coKer.
simpl in |- *.
Lemma Leibnitz_set_prop_rev :
forall (A : Type) (x y : Leibnitz_set A), x = y -> Equal x y.
Lemma ideal_prop4 :
forall (I : ideal) (x : R), in_part x I -> in_part (group_inverse R x) I.
Lemma coKer_prop : forall x : G, in_part (f x) coKer.
simpl in |- *.