intro (_ : n ≃ 0)
case mpr.left
ℕ : Type
inst✝⁵ : Core ℕ
inst✝⁴ : Induction ℕ
inst✝³ : Addition ℕ
inst✝² : Sign ℕ
inst✝¹ : Order ℕ
inst✝ : Multiplication ℕ
n m : ℕ
x✝ : n ≃ 0 ∨ m ≃ 0
⊢ n ≃ 0 → n * m ≃ 0
case mpr.left
ℕ : Type
inst✝⁵ : Core ℕ
inst✝⁴ : Induction ℕ
inst✝³ : Addition ℕ
inst✝² : Sign ℕ
inst✝¹ : Order ℕ
inst✝ : Multiplication ℕ
n m : ℕ
x✝¹ : n ≃ 0 ∨ m ≃ 0
x✝ : n ≃ 0
⊢ n * m ≃ 0