intro (_ : n ≃ m)
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n m : ℕ
⊢ n ≃ m → n + 0 ≃ 0 + m
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n m : ℕ
x✝ : n ≃ m
⊢ n + 0 ≃ 0 + m