calc
  0 * m ≃ _ := zero_mul
  0     ≃ _ := Rel.symm mul_zero
  m * 0 ≃ _ := Rel.refl
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
⊢ 0 * m ≃ m * 0
no goals