Theorem: LO.FirstOrder.Arith.Hierarchy.zero_iff_delta_zero (Logic/FirstOrder/Arith/Hierarchy.lean)

State before:
L : Language
inst✝ : L.LT
μ : Type v
n : ℕ
Γ : Polarity
p : Semiformula L μ n
⊢ Hierarchy Γ 0 p ↔ DeltaZero p
Tactic:
simp[DeltaZero, pi_zero_iff_sigma_zero]
State after:
L : Language
inst✝ : L.LT
μ : Type v
n : ℕ
Γ : Polarity
p : Semiformula L μ n
⊢ Hierarchy Γ 0 p ↔ Hierarchy 𝚺 0 p

State before:
L : Language
inst✝ : L.LT
μ : Type v
n : ℕ
Γ : Polarity
p : Semiformula L μ n
⊢ Hierarchy Γ 0 p ↔ Hierarchy 𝚺 0 p
Tactic:
apply zero_iff
State after:
no goals