Theorem: LO.FirstOrder.Rew.eq_ex_iff (Logic/FirstOrder/Basic/Syntax/Rew.lean)

State before:
L : Language
L₁ : Language
L₂ : Language
L₃ : Language
ξ : Type u_1
ξ₁ : Type u_2
ξ₂ : Type u_3
ξ₃ : Type u_4
n n₁ n₂✝ n₂ m m₁ m₂ m₃ : ℕ
ω : Rew L ξ₁ n₁ ξ₂ n₂
p : Semiformula L ξ₁ n₁
q : Semiformula L ξ₂ (n₂ + 1)
⊢ ω.hom p = ∃' q ↔ ∃ p', ω.q.hom p' = q ∧ p = ∃' p'
Tactic:
cases p using Semiformula.rec' <;> simp[Rew.rel, Rew.nrel]
State after:
no goals