exact Set.Subset.trans (by simp_all) hΩ'
case mpr.intro.left
α : Type u_1
inst✝² : DecidableEq α
inst✝¹ : Inhabited α
L : DeductionParameter α
inst✝ : L.Normal
Ω Ω₁ Ω₂ : MCT L
p : Formula α
n : ℕ
hp : □^[n]p ∉ Ω.theory
Ω' : MCT L
hΩ' : insert (~p) (□''⁻¹^[n]Ω.theory) ⊆ Ω'.theory
⊢ □''⁻¹^[n]Ω.theory ⊆ Ω'.theory
no goals