. intro h;
  apply Context.provable_iff.mpr;
  obtain ⟨Γ, hΓ₁, hΓ₂⟩ := iff_insert_notParametricConsistent.mp h;
  existsi Γ;
  constructor;
  . exact hΓ₁;
  . exact FiniteContext.ofDef'! $ imp_swap'! $ andImplyIffImplyImply'!.mp hΓ₂;
case mpr
α : Type u_1
inst✝² : DecidableEq α
inst✝¹ : Inhabited α
L : DeductionParameter α
inst✝ : L.Normal
T : Theory α
p : Formula α
⊢ ¬(L)-Consistent insert p T → T *⊢[L]! ~p
no goals