apply Iff.intro
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n m : ℕ
⊢ n + 0 ≃ 0 + m ↔ n ≃ m
case mp
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n m : ℕ
⊢ n + 0 ≃ 0 + m → n ≃ m

case mpr
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n m : ℕ
⊢ n ≃ m → n + 0 ≃ 0 + m