have h5 : (i: ℚ) < 330 := by norm_cast
i : ℕ
hi : i < 330
h1 : ↑(1319 - i) = 1319 - ↑i
⊢ (660 + ↑i) * (1319 - ↑i) ≠ 0
i : ℕ
hi : i < 330
h1 : ↑(1319 - i) = 1319 - ↑i
h5 : ↑i < 330
⊢ (660 + ↑i) * (1319 - ↑i) ≠ 0