exact mul_preserves_positive.mpr (And.intro ‹Positive n› ‹Positive m›)
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 : Positive n
x✝ : Positive m
⊢ Positive (n * m)
no goals