∀ {N : ℕ} (χ : DirichletCharacter ℂ N) [inst : NeZero N] {y : ℝ},
  y ≠ 0 ∨ χ ≠ 1 →
    DirichletCharacter.LFunction χ (1 + Complex.I * ↑y) = 0 →
      (fun x => DirichletCharacter.LFunction χ (1 + ↑x + Complex.I * ↑y)) =O[nhdsWithin 0 (Set.Ioi 0)] fun x => ↑x