. intro h p hp; exact multiframe_def_multibox.mp h hp;
case mp
α : Type u_1
inst✝⁴ : DecidableEq α
inst✝³ : Inhabited α
L : DeductionParameter α
inst✝² : L.Normal
inst✝¹ : Minimal L
inst✝ : Inhabited (MCT L)
n : ℕ
Ω₁ Ω₂ : (CanonicalFrame L).World
⊢ Ω₁ ≺^[n] Ω₂ → ∀ {p : Formula α}, p ∈ □''⁻¹^[n]Ω₁.theory → p ∈ Ω₂.theory

case mpr
α : Type u_1
inst✝⁴ : DecidableEq α
inst✝³ : Inhabited α
L : DeductionParameter α
inst✝² : L.Normal
inst✝¹ : Minimal L
inst✝ : Inhabited (MCT L)
n : ℕ
Ω₁ Ω₂ : (CanonicalFrame L).World
⊢ (∀ {p : Formula α}, p ∈ □''⁻¹^[n]Ω₁.theory → p ∈ Ω₂.theory) → Ω₁ ≺^[n] Ω₂
case mpr
α : Type u_1
inst✝⁴ : DecidableEq α
inst✝³ : Inhabited α
L : DeductionParameter α
inst✝² : L.Normal
inst✝¹ : Minimal L
inst✝ : Inhabited (MCT L)
n : ℕ
Ω₁ Ω₂ : (CanonicalFrame L).World
⊢ (∀ {p : Formula α}, p ∈ □''⁻¹^[n]Ω₁.theory → p ∈ Ω₂.theory) → Ω₁ ≺^[n] Ω₂