Update Basic.lean
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Stefan Kebekus
2025-12-04 17:05:57 +01:00
parent c308fc2403
commit b7ade87d22

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@@ -1,60 +1,7 @@
import Mathlib.Analysis.Meromorphic.Basic
import Mathlib.Analysis.Calculus.Deriv.Mul
import Mathlib.Analysis.Calculus.Deriv.ZPow
import Mathlib.Analysis.Calculus.Deriv.Shift
import Mathlib
open MeromorphicOn Real Set Classical Topology
@[simp]
theorem eventually_nhdsNE_eventually_nhds_iff_eventually_nhdsNE
{α : Type*} [TopologicalSpace α] [T1Space α] {a : α} {p : α Prop} :
( y in 𝓝[] a, x in 𝓝 y, p x) x in 𝓝[] a, p x := by
nth_rw 2 [ eventually_eventually_nhdsWithin]
constructor
· intro h
filter_upwards [h] with _ hy
exact eventually_nhdsWithin_of_eventually_nhds hy
· intro h
filter_upwards [h, eventually_nhdsWithin_of_forall fun _ a a] with _ _ _
simp_all [IsOpen.nhdsWithin_eq]
theorem Filter.EventuallyEq.nhdsNE_deriv
{𝕜 : Type u} [NontriviallyNormedField 𝕜]
{F : Type v} [NormedAddCommGroup F] [NormedSpace 𝕜 F] {f f₁ : 𝕜 F} {x : 𝕜}
(h : f₁ =[𝓝[] x] f) :
deriv f₁ =[𝓝[] x] deriv f := by
rw [Filter.EventuallyEq, eventually_nhdsNE_eventually_nhds_iff_eventually_nhdsNE] at *
filter_upwards [h] with y hy
apply Filter.EventuallyEq.deriv hy
variable
{𝕜 : Type*} [NontriviallyNormedField 𝕜]
{E : Type*} [NormedAddCommGroup E] [NormedSpace 𝕜 E] [CompleteSpace E]
{U : Set 𝕜} {f g : 𝕜 E} {a : WithTop E} {a₀ : E}
@[fun_prop]
theorem AnalyticAt.deriv₁
{𝕜 : Type u} [NontriviallyNormedField 𝕜]
{F : Type v} [NormedAddCommGroup F] [NormedSpace 𝕜 F] [CompleteSpace F]
{f : 𝕜 F} {x : 𝕜}
(h : AnalyticAt 𝕜 f x) :
AnalyticAt 𝕜 (deriv f) x := by
obtain r, hr, h := h.exists_ball_analyticOnNhd
exact h.deriv x (by simp [hr])
/-- Derivatives of meromorphic functions are meromorphic. -/
@[fun_prop]
theorem meromorphicAt_deriv {f : 𝕜 E} {x : 𝕜} (h : MeromorphicAt f x) :
MeromorphicAt (deriv f) x := by
rw [MeromorphicAt.iff_eventuallyEq_zpow_smul_analyticAt] at h
obtain n, g, h₁g, h₂g := h
have : deriv (fun z (z - x) ^ n g z)
=[𝓝[] x] fun z (n * (z - x) ^ (n - 1)) g z + (z - x) ^ n deriv g z := by
filter_upwards [eventually_nhdsWithin_of_eventually_nhds h₁g.eventually_analyticAt,
eventually_nhdsWithin_of_forall fun _ a a] with z₀ h₁ h₂
rw [deriv_smul (DifferentiableAt.zpow (by fun_prop) (by simp_all [sub_ne_zero_of_ne h₂])) (by fun_prop),
add_comm, deriv_comp_sub_const (f := (· ^ n))]
aesop
rw [MeromorphicAt.meromorphicAt_congr (Filter.EventuallyEq.nhdsNE_deriv h₂g),
MeromorphicAt.meromorphicAt_congr this]
fun_prop
lemma meromorphic_measurable {f : } (h : MeromorphicOn f ) :
Measurable f := by
sorry