import Nevanlinna.holomorphic def zeroDivisor {f : ℂ → ℂ} {R : ℝ} (h₁f : ∀ z ∈ Metric.closedBall z R, HolomorphicAt f z) (h₂f : ∃ z ∈ Metric.closedBall z R, f z ≠ 0) : ℂ → ℕ := by sorry