intro n (_ : step n + m ≃ 0)
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n m : ℕ
⊢ ∀ (m_1 : ℕ), step m_1 + m ≃ 0 → step m_1 ≃ 0 ∧ m ≃ 0
ℕ : Type
inst✝² : Core ℕ
inst✝¹ : Induction ℕ
inst✝ : Addition ℕ
n✝ m n : ℕ
x✝ : step n + m ≃ 0
⊢ step n ≃ 0 ∧ m ≃ 0