proposition: Lemma nExist (T : System) (f : Formula) (v : nat): SysPrf T (allH v, ~ f)%fol -> SysPrf T (~ (exH v, f))%fol.
proof: Proof. apply (nExist LNN). Qed.
imports: Coq(Arith Ensembles List) LibHyps(LibHyps) hydras(MoreLibHyps NewNotations)