intro (_ : Positive x)
x : ℤ
mul_ident : AA.Identity (coe 1) fun x x_1 => x * x_1
⊢ Positive x → ∃ n, Positive n ∧ x ≃ coe n
x : ℤ
mul_ident : AA.Identity (coe 1) fun x x_1 => x * x_1
x✝ : Positive x
⊢ ∃ n, Positive n ∧ x ≃ coe n