. rintro ⟨hp, hq⟩;
  apply membership_iff.mpr;
  exact conj₃'! (membership_iff.mp hp) (membership_iff.mp hq);
case mpr
α : Type u_1
inst✝² : DecidableEq α
inst✝¹ : Inhabited α
L : DeductionParameter α
inst✝ : L.Normal
Ω Ω₁ Ω₂ : MCT L
p q : Formula α
⊢ p ∈ Ω.theory ∧ q ∈ Ω.theory → p ⋏ q ∈ Ω.theory
no goals