rcases H with rfl
L : Language
ξ₁ : Type u_2
n₁ : ℕ
ξ₂ : Type u_3
n₂ : ℕ
p : Semiformula L ξ₁ n₁
ω ω' : Rew L ξ₁ n₁ ξ₂ n₂
H : ω = (Rew.castLE ⋯).comp ω'
⊢ ∀* ω.hom p = ∀* ω'.hom p
L : Language
ξ₁ : Type u_2
n₁ : ℕ
ξ₂ : Type u_3
n₂ : ℕ
p : Semiformula L ξ₁ n₁
ω' : Rew L ξ₁ n₁ ξ₂ n₂
⊢ ∀* ((Rew.castLE ⋯).comp ω').hom p = ∀* ω'.hom p