Section C.
Parameter g : forall m : nat, m <> 0 -> Prop.
Parameter f : forall (m : nat) (H : m <> 0), g m H.
Variable n : nat.
Variable ap_n : n <> 0.
Let delta := f n ap_n.
lia.
Qed.
End C.

(* Problem of dependencies *)
Lemma lem8 : forall H : 0 = 0 -> 0 = 0, H = H -> 0 = 0.