import Mathlib.Analysis.Meromorphic.Basic import Mathlib.Analysis.Meromorphic.Order open MeromorphicOn Metric Real Set Classical variable {𝕜 : Type*} [NontriviallyNormedField 𝕜] [CompleteSpace 𝕜] /-- Derivatives of meromorphic functions are meromorphic. -/ theorem meromorphicAt_deriv_of_order_eq_top {f : 𝕜 → 𝕜} {x : 𝕜} (h : MeromorphicAt f x) (h₁ : h.order ≠ ⊤) : MeromorphicAt (deriv f) x := by have := h.eventually_analyticAt obtain ⟨n, hn⟩ := h let g : 𝕜 → 𝕜 := sorry rw [MeromorphicAt.meromorphicAt_congr] sorry