File: Mathlib/Analysis/Complex/CauchyIntegral.lean

full_name: Complex.integral_boundary_rect_of_hasFDerivAt_real_off_countable
code: /-- Suppose that a function `f : ℂ → E` is continuous on a closed rectangle with opposite corners at
`z w : ℂ`, is *real* differentiable at all but countably many points of the corresponding open
rectangle, and $\frac{\partial f}{\partial \bar z}$ is integrable on this rectangle. Then the
integral of `f` over the boundary of the rectangle is equal to the integral of
$2i\frac{\partial f}{\partial \bar z}=i\frac{\partial f}{\partial x}-\frac{\partial f}{\partial y}$
over the rectangle. -/
theorem integral_boundary_rect_of_hasFDerivAt_real_off_countable (f : ℂ → E) (f' : ℂ → ℂ →L[ℝ] E)
    (z w : ℂ) (s : Set ℂ) (hs : s.Countable)
    (Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
    (Hd : ∀ x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im) \ s,
      HasFDerivAt f (f' x) x)
    (Hi : IntegrableOn (fun z => I • f' z 1 - f' z I) ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
    (∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
      I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
      I • ∫ y : ℝ in z.im..w.im, f (re z + y * I) =
      ∫ x : ℝ in z.re..w.re, ∫ y : ℝ in z.im..w.im, I • f' (x + y * I) 1 - f' (x + y * I) I 
goal: (((∫ (x : ℝ) in z.re..w.re, f (↑x + ↑z.im * Complex.I)) - ∫ (x : ℝ) in z.re..w.re, f (↑x + ↑w.im * Complex.I)) +
      Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑w.re + ↑y * Complex.I)) -
    Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * Complex.I) =
  ∫ (x : ℝ) in z.re..w.re,
    ∫ (y : ℝ) in z.im..w.im, Complex.I • (f' (↑x + ↑y * Complex.I)) 1 - (f' (↑x + ↑y * Complex.I)) Complex.I

full_name: Complex.integral_boundary_rect_of_continuousOn_of_hasFDerivAt_real
code: /-- Suppose that a function `f : ℂ → E` is continuous on a closed rectangle with opposite corners at
`z w : ℂ`, is *real* differentiable on the corresponding open rectangle, and
$\frac{\partial f}{\partial \bar z}$ is integrable on this rectangle. Then the integral of `f` over
the boundary of the rectangle is equal to the integral of
$2i\frac{\partial f}{\partial \bar z}=i\frac{\partial f}{\partial x}-\frac{\partial f}{\partial y}$
over the rectangle. -/
theorem integral_boundary_rect_of_continuousOn_of_hasFDerivAt_real (f : ℂ → E) (f' : ℂ → ℂ →L[ℝ] E)
    (z w : ℂ) (Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
    (Hd : ∀ x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im),
      HasFDerivAt f (f' x) x)
    (Hi : IntegrableOn (fun z => I • f' z 1 - f' z I) ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
    (∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
      I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
      I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) =
      ∫ x : ℝ in z.re..w.re, ∫ y : ℝ in z.im..w.im, I • f' (x + y * I) 1 - f' (x + y * I) I 
goal: (((∫ (x : ℝ) in z.re..w.re, f (↑x + ↑z.im * Complex.I)) - ∫ (x : ℝ) in z.re..w.re, f (↑x + ↑w.im * Complex.I)) +
      Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑w.re + ↑y * Complex.I)) -
    Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * Complex.I) =
  ∫ (x : ℝ) in z.re..w.re,
    ∫ (y : ℝ) in z.im..w.im, Complex.I • (f' (↑x + ↑y * Complex.I)) 1 - (f' (↑x + ↑y * Complex.I)) Complex.I

full_name: Complex.integral_boundary_rect_of_differentiableOn_real
code: /-- Suppose that a function `f : ℂ → E` is *real* differentiable on a closed rectangle with opposite
corners at `z w : ℂ` and $\frac{\partial f}{\partial \bar z}$ is integrable on this rectangle. Then
the integral of `f` over the boundary of the rectangle is equal to the integral of
$2i\frac{\partial f}{\partial \bar z}=i\frac{\partial f}{\partial x}-\frac{\partial f}{\partial y}$
over the rectangle. -/
theorem integral_boundary_rect_of_differentiableOn_real (f : ℂ → E) (z w : ℂ)
    (Hd : DifferentiableOn ℝ f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
    (Hi : IntegrableOn (fun z => I • fderiv ℝ f z 1 - fderiv ℝ f z I)
      ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
    (∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
      I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
      I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) =
      ∫ x : ℝ in z.re..w.re, ∫ y : ℝ in z.im..w.im,
        I • fderiv ℝ f (x + y * I) 1 - fderiv ℝ f (x + y * I) I 
goal: (((∫ (x : ℝ) in z.re..w.re, f (↑x + ↑z.im * Complex.I)) - ∫ (x : ℝ) in z.re..w.re, f (↑x + ↑w.im * Complex.I)) +
      Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑w.re + ↑y * Complex.I)) -
    Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * Complex.I) =
  ∫ (x : ℝ) in z.re..w.re,
    ∫ (y : ℝ) in z.im..w.im,
      Complex.I • (fderiv ℝ f (↑x + ↑y * Complex.I)) 1 - (fderiv ℝ f (↑x + ↑y * Complex.I)) Complex.I

full_name: Complex.integral_boundary_rect_eq_zero_of_differentiable_on_off_countable
code: /-- **Cauchy-Goursat theorem** for a rectangle: the integral of a complex differentiable function
over the boundary of a rectangle equals zero. More precisely, if `f` is continuous on a closed
rectangle and is complex differentiable at all but countably many points of the corresponding open
rectangle, then its integral over the boundary of the rectangle equals zero. -/
theorem integral_boundary_rect_eq_zero_of_differentiable_on_off_countable (f : ℂ → E) (z w : ℂ)
    (s : Set ℂ) (hs : s.Countable) (Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
    (Hd : ∀ x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im) \ s,
      DifferentiableAt ℂ f x) :
    (∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
      I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
      I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) = 0 
goal: (((∫ (x : ℝ) in z.re..w.re, f (↑x + ↑z.im * Complex.I)) - ∫ (x : ℝ) in z.re..w.re, f (↑x + ↑w.im * Complex.I)) +
      Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑w.re + ↑y * Complex.I)) -
    Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * Complex.I) =
  0

full_name: Complex.integral_boundary_rect_eq_zero_of_continuousOn_of_differentiableOn
code: /-- **Cauchy-Goursat theorem for a rectangle**: the integral of a complex differentiable function
over the boundary of a rectangle equals zero. More precisely, if `f` is continuous on a closed
rectangle and is complex differentiable on the corresponding open rectangle, then its integral over
the boundary of the rectangle equals zero. -/
theorem integral_boundary_rect_eq_zero_of_continuousOn_of_differentiableOn (f : ℂ → E) (z w : ℂ)
    (Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
    (Hd : DifferentiableOn ℂ f
      (Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im))) :
    (∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
      I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
      I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) = 0 
goal: (((∫ (x : ℝ) in z.re..w.re, f (↑x + ↑z.im * Complex.I)) - ∫ (x : ℝ) in z.re..w.re, f (↑x + ↑w.im * Complex.I)) +
      Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑w.re + ↑y * Complex.I)) -
    Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * Complex.I) =
  0

full_name: Complex.integral_boundary_rect_eq_zero_of_differentiableOn
code: /-- **Cauchy-Goursat theorem** for a rectangle: the integral of a complex differentiable function
over the boundary of a rectangle equals zero. More precisely, if `f` is complex differentiable on a
closed rectangle, then its integral over the boundary of the rectangle equals zero. -/
theorem integral_boundary_rect_eq_zero_of_differentiableOn (f : ℂ → E) (z w : ℂ)
    (H : DifferentiableOn ℂ f ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
    (∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
      I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
      I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) = 0 
goal: (((∫ (x : ℝ) in z.re..w.re, f (↑x + ↑z.im * Complex.I)) - ∫ (x : ℝ) in z.re..w.re, f (↑x + ↑w.im * Complex.I)) +
      Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑w.re + ↑y * Complex.I)) -
    Complex.I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * Complex.I) =
  0

full_name: Complex.circleIntegral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable
code: /-- If `f : ℂ → E` is continuous on the closed annulus `r ≤ ‖z - c‖ ≤ R`, `0 < r ≤ R`,
and is complex differentiable at all but countably many points of its interior,
then the integrals of `f z / (z - c)` (formally, `(z - c)⁻¹ • f z`)
over the circles `‖z - c‖ = r` and `‖z - c‖ = R` are equal to each other. -/
theorem circleIntegral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable {c : ℂ}
    {r R : ℝ} (h0 : 0 < r) (hle : r ≤ R) {f : ℂ → E} {s : Set ℂ} (hs : s.Countable)
    (hc : ContinuousOn f (closedBall c R \ ball c r))
    (hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z) :
    (∮ z in C(c, R), (z - c)⁻¹ • f z) = ∮ z in C(c, r), (z - c)⁻¹ • f z 
goal: (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, r), (z - c)⁻¹ • f z

full_name: Complex.circleIntegral_eq_of_differentiable_on_annulus_off_countable
code: /-- **Cauchy-Goursat theorem** for an annulus. If `f : ℂ → E` is continuous on the closed annulus
`r ≤ ‖z - c‖ ≤ R`, `0 < r ≤ R`, and is complex differentiable at all but countably many points of
its interior, then the integrals of `f` over the circles `‖z - c‖ = r` and `‖z - c‖ = R` are equal
to each other. -/
theorem circleIntegral_eq_of_differentiable_on_annulus_off_countable {c : ℂ} {r R : ℝ} (h0 : 0 < r)
    (hle : r ≤ R) {f : ℂ → E} {s : Set ℂ} (hs : s.Countable)
    (hc : ContinuousOn f (closedBall c R \ ball c r))
    (hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z) :
    (∮ z in C(c, R), f z) = ∮ z in C(c, r), f z 
goal: (∮ (z : ℂ) in C(c, R), f z) = ∮ (z : ℂ) in C(c, r), f z

full_name: Complex.circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto
code: /-- **Cauchy integral formula** for the value at the center of a disc. If `f` is continuous on a
punctured closed disc of radius `R`, is differentiable at all but countably many points of the
interior of this disc, and has a limit `y` at the center of the disc, then the integral
$\oint_{‖z-c‖=R} \frac{f(z)}{z-c}\,dz$ is equal to `2πiy`. -/
theorem circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto {c : ℂ}
    {R : ℝ} (h0 : 0 < R) {f : ℂ → E} {y : E} {s : Set ℂ} (hs : s.Countable)
    (hc : ContinuousOn f (closedBall c R \ {c}))
    (hd : ∀ z ∈ (ball c R \ {c}) \ s, DifferentiableAt ℂ f z) (hy : Tendsto f (𝓝[{c}ᶜ] c) (𝓝 y)) :
    (∮ z in C(c, R), (z - c)⁻¹ • f z) = (2 * π * I : ℂ) • y 
goal: (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = (2 * ↑π * Complex.I) • y

full_name: Complex.circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable
code: /-- **Cauchy integral formula** for the value at the center of a disc. If `f : ℂ → E` is continuous
on a closed disc of radius `R` and is complex differentiable at all but countably many points of its
interior, then the integral $\oint_{|z-c|=R} \frac{f(z)}{z-c}\,dz$ is equal to `2πiy`. -/
theorem circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable {R : ℝ} (h0 : 0 < R)
    {f : ℂ → E} {c : ℂ} {s : Set ℂ} (hs : s.Countable) (hc : ContinuousOn f (closedBall c R))
    (hd : ∀ z ∈ ball c R \ s, DifferentiableAt ℂ f z) :
    (∮ z in C(c, R), (z - c)⁻¹ • f z) = (2 * π * I : ℂ) • f c 
goal: (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = (2 * ↑π * Complex.I) • f c

full_name: Complex.circleIntegral_eq_zero_of_differentiable_on_off_countable
code: /-- **Cauchy-Goursat theorem** for a disk: if `f : ℂ → E` is continuous on a closed disk
`{z | ‖z - c‖ ≤ R}` and is complex differentiable at all but countably many points of its interior,
then the integral $\oint_{|z-c|=R}f(z)\,dz$ equals zero. -/
theorem circleIntegral_eq_zero_of_differentiable_on_off_countable {R : ℝ} (h0 : 0 ≤ R) {f : ℂ → E}
    {c : ℂ} {s : Set ℂ} (hs : s.Countable) (hc : ContinuousOn f (closedBall c R))
    (hd : ∀ z ∈ ball c R \ s, DifferentiableAt ℂ f z) : (∮ z in C(c, R), f z) = 0 
goal: (∮ (z : ℂ) in C(c, R), f z) = 0

full_name: Complex.circleIntegral_sub_inv_smul_of_differentiable_on_off_countable_aux
code: /-- An auxiliary lemma for
`Complex.circleIntegral_sub_inv_smul_of_differentiable_on_off_countable`. This lemma assumes
`w ∉ s` while the main lemma drops this assumption. -/
theorem circleIntegral_sub_inv_smul_of_differentiable_on_off_countable_aux {R : ℝ} {c w : ℂ}
    {f : ℂ → E} {s : Set ℂ} (hs : s.Countable) (hw : w ∈ ball c R \ s)
    (hc : ContinuousOn f (closedBall c R)) (hd : ∀ x ∈ ball c R \ s, DifferentiableAt ℂ f x) :
    (∮ z in C(c, R), (z - w)⁻¹ • f z) = (2 * π * I : ℂ) • f w 
goal: (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • f z) = (2 * ↑π * Complex.I) • f w

full_name: Complex.two_pi_I_inv_smul_circleIntegral_sub_inv_smul_of_differentiable_on_off_countable
code: /-- **Cauchy integral formula**: if `f : ℂ → E` is continuous on a closed disc of radius `R` and is
complex differentiable at all but countably many points of its interior, then for any `w` in this
interior we have $\frac{1}{2πi}\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=f(w)$.
-/
theorem two_pi_I_inv_smul_circleIntegral_sub_inv_smul_of_differentiable_on_off_countable {R : ℝ}
    {c w : ℂ} {f : ℂ → E} {s : Set ℂ} (hs : s.Countable) (hw : w ∈ ball c R)
    (hc : ContinuousOn f (closedBall c R)) (hd : ∀ x ∈ ball c R \ s, DifferentiableAt ℂ f x) :
    ((2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z) = f w 
goal: ((2 * ↑π * Complex.I)⁻¹ • ∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • f z) = f w

full_name: Complex.circleIntegral_sub_inv_smul_of_differentiable_on_off_countable
code: /-- **Cauchy integral formula**: if `f : ℂ → E` is continuous on a closed disc of radius `R` and is
complex differentiable at all but countably many points of its interior, then for any `w` in this
interior we have $\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=2πif(w)$.
-/
theorem circleIntegral_sub_inv_smul_of_differentiable_on_off_countable {R : ℝ} {c w : ℂ} {f : ℂ → E}
    {s : Set ℂ} (hs : s.Countable) (hw : w ∈ ball c R) (hc : ContinuousOn f (closedBall c R))
    (hd : ∀ x ∈ ball c R \ s, DifferentiableAt ℂ f x) :
    (∮ z in C(c, R), (z - w)⁻¹ • f z) = (2 * π * I : ℂ) • f w 
goal: (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • f z) = (2 * ↑π * Complex.I) • f w

full_name: DiffContOnCl.circleIntegral_sub_inv_smul
code: /-- **Cauchy integral formula**: if `f : ℂ → E` is complex differentiable on an open disc and is
continuous on its closure, then for any `w` in this open ball we have
$\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=2πif(w)$. -/
theorem _root_.DiffContOnCl.circleIntegral_sub_inv_smul {R : ℝ} {c w : ℂ} {f : ℂ → E}
    (h : DiffContOnCl ℂ f (ball c R)) (hw : w ∈ ball c R) :
    (∮ z in C(c, R), (z - w)⁻¹ • f z) = (2 * π * I : ℂ) • f w 
goal: (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • f z) = (2 * ↑π * Complex.I) • f w

full_name: DiffContOnCl.two_pi_i_inv_smul_circleIntegral_sub_inv_smul
code: /-- **Cauchy integral formula**: if `f : ℂ → E` is complex differentiable on an open disc and is
continuous on its closure, then for any `w` in this open ball we have
$\frac{1}{2πi}\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=f(w)$. -/
theorem _root_.DiffContOnCl.two_pi_i_inv_smul_circleIntegral_sub_inv_smul {R : ℝ} {c w : ℂ}
    {f : ℂ → E} (hf : DiffContOnCl ℂ f (ball c R)) (hw : w ∈ ball c R) :
    ((2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z) = f w 
goal: ((2 * ↑π * Complex.I)⁻¹ • ∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • f z) = f w

full_name: DifferentiableOn.circleIntegral_sub_inv_smul
code: /-- **Cauchy integral formula**: if `f : ℂ → E` is complex differentiable on a closed disc of radius
`R`, then for any `w` in its interior we have $\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=2πif(w)$. -/
theorem _root_.DifferentiableOn.circleIntegral_sub_inv_smul {R : ℝ} {c w : ℂ} {f : ℂ → E}
    (hd : DifferentiableOn ℂ f (closedBall c R)) (hw : w ∈ ball c R) :
    (∮ z in C(c, R), (z - w)⁻¹ • f z) = (2 * π * I : ℂ) • f w 
goal: (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • f z) = (2 * ↑π * Complex.I) • f w

full_name: Complex.circleIntegral_div_sub_of_differentiable_on_off_countable
code: /-- **Cauchy integral formula**: if `f : ℂ → ℂ` is continuous on a closed disc of radius `R` and is
complex differentiable at all but countably many points of its interior, then for any `w` in this
interior we have $\oint_{|z-c|=R}\frac{f(z)}{z-w}dz=2\pi i\,f(w)$.
-/
theorem circleIntegral_div_sub_of_differentiable_on_off_countable {R : ℝ} {c w : ℂ} {s : Set ℂ}
    (hs : s.Countable) (hw : w ∈ ball c R) {f : ℂ → ℂ} (hc : ContinuousOn f (closedBall c R))
    (hd : ∀ z ∈ ball c R \ s, DifferentiableAt ℂ f z) :
    (∮ z in C(c, R), f z / (z - w)) = 2 * π * I * f w 
goal: (∮ (z : ℂ) in C(c, R), f z / (z - w)) = 2 * ↑π * Complex.I * f w

full_name: Complex.hasFPowerSeriesOnBall_of_differentiable_off_countable
code: /-- If `f : ℂ → E` is continuous on a closed ball of positive radius and is differentiable at all
but countably many points of the corresponding open ball, then it is analytic on the open ball with
coefficients of the power series given by Cauchy integral formulas. -/
theorem hasFPowerSeriesOnBall_of_differentiable_off_countable {R : ℝ≥0} {c : ℂ} {f : ℂ → E}
    {s : Set ℂ} (hs : s.Countable) (hc : ContinuousOn f (closedBall c R))
    (hd : ∀ z ∈ ball c R \ s, DifferentiableAt ℂ f z) (hR : 0 < R) :
    HasFPowerSeriesOnBall f (cauchyPowerSeries f c R) c R 
goal: HasFPowerSeriesOnBall f (cauchyPowerSeries f c ↑R) c ↑R

full_name: DiffContOnCl.hasFPowerSeriesOnBall
code: /-- If `f : ℂ → E` is complex differentiable on an open disc of positive radius and is continuous
on its closure, then it is analytic on the open disc with coefficients of the power series given by
Cauchy integral formulas. -/
theorem _root_.DiffContOnCl.hasFPowerSeriesOnBall {R : ℝ≥0} {c : ℂ} {f : ℂ → E}
    (hf : DiffContOnCl ℂ f (ball c R)) (hR : 0 < R) :
    HasFPowerSeriesOnBall f (cauchyPowerSeries f c R) c R 
goal: HasFPowerSeriesOnBall f (cauchyPowerSeries f c ↑R) c ↑R

full_name: DifferentiableOn.hasFPowerSeriesOnBall
code: /-- If `f : ℂ → E` is complex differentiable on a closed disc of positive radius, then it is
analytic on the corresponding open disc, and the coefficients of the power series are given by
Cauchy integral formulas. See also
`Complex.hasFPowerSeriesOnBall_of_differentiable_off_countable` for a version of this lemma with
weaker assumptions. -/
protected theorem _root_.DifferentiableOn.hasFPowerSeriesOnBall {R : ℝ≥0} {c : ℂ} {f : ℂ → E}
    (hd : DifferentiableOn ℂ f (closedBall c R)) (hR : 0 < R) :
    HasFPowerSeriesOnBall f (cauchyPowerSeries f c R) c R 
goal: HasFPowerSeriesOnBall f (cauchyPowerSeries f c ↑R) c ↑R

full_name: DifferentiableOn.analyticAt
code: /-- If `f : ℂ → E` is complex differentiable on some set `s`, then it is analytic at any point `z`
such that `s ∈ 𝓝 z` (equivalently, `z ∈ interior s`). -/
protected theorem _root_.DifferentiableOn.analyticAt {s : Set ℂ} {f : ℂ → E} {z : ℂ}
    (hd : DifferentiableOn ℂ f s) (hz : s ∈ 𝓝 z) : AnalyticAt ℂ f z 
goal: AnalyticAt ℂ f z

full_name: DifferentiableOn.analyticOn
code: theorem _root_.DifferentiableOn.analyticOn {s : Set ℂ} {f : ℂ → E} (hd : DifferentiableOn ℂ f s)
    (hs : IsOpen s) : AnalyticOn ℂ f s 
goal: AnalyticOn ℂ f s

full_name: DifferentiableOn.contDiffOn
code: /-- If `f : ℂ → E` is complex differentiable on some open set `s`, then it is continuously
differentiable on `s`. -/
protected theorem _root_.DifferentiableOn.contDiffOn {s : Set ℂ} {f : ℂ → E} {n : ℕ}
    (hd : DifferentiableOn ℂ f s) (hs : IsOpen s) : ContDiffOn ℂ n f s 
goal: ContDiffOn ℂ (↑n) f s

full_name: Differentiable.analyticAt
code: /-- A complex differentiable function `f : ℂ → E` is analytic at every point. -/
protected theorem _root_.Differentiable.analyticAt {f : ℂ → E} (hf : Differentiable ℂ f) (z : ℂ) :
    AnalyticAt ℂ f z 
goal: AnalyticAt ℂ f z

full_name: Differentiable.contDiff
code: /-- A complex differentiable function `f : ℂ → E` is continuously differentiable at every point. -/
protected theorem _root_.Differentiable.contDiff {f : ℂ → E} (hf : Differentiable ℂ f) {n : ℕ∞} :
    ContDiff ℂ n f 
goal: ContDiff ℂ n f

full_name: Differentiable.hasFPowerSeriesOnBall
code: /-- When `f : ℂ → E` is differentiable, the `cauchyPowerSeries f z R` represents `f` as a power
series centered at `z` in the entirety of `ℂ`, regardless of `R : ℝ≥0`, with `0 < R`. -/
protected theorem _root_.Differentiable.hasFPowerSeriesOnBall {f : ℂ → E} (h : Differentiable ℂ f)
    (z : ℂ) {R : ℝ≥0} (hR : 0 < R) : HasFPowerSeriesOnBall f (cauchyPowerSeries f z R) z ∞ 
goal: HasFPowerSeriesOnBall f (cauchyPowerSeries f z ↑R) z ⊤

full_name: Complex.analyticOn_iff_differentiableOn
code: /-- On an open set, `f : ℂ → E` is analytic iff it is differentiable -/
theorem analyticOn_iff_differentiableOn {f : ℂ → E} {s : Set ℂ} (o : IsOpen s) :
    AnalyticOn ℂ f s ↔ DifferentiableOn ℂ f s 
goal: AnalyticOn ℂ f s ↔ DifferentiableOn ℂ f s

full_name: Complex.analyticOn_univ_iff_differentiable
code: /-- `f : ℂ → E` is entire iff it's differentiable -/
theorem analyticOn_univ_iff_differentiable {f : ℂ → E} :
    AnalyticOn ℂ f univ ↔ Differentiable ℂ f 
goal: AnalyticOn ℂ f Set.univ ↔ Differentiable ℂ f

full_name: Complex.analyticAt_iff_eventually_differentiableAt
code: /-- `f : ℂ → E` is analytic at `z` iff it's differentiable near `z` -/
theorem analyticAt_iff_eventually_differentiableAt {f : ℂ → E} {c : ℂ} :
    AnalyticAt ℂ f c ↔ ∀ᶠ z in 𝓝 c, DifferentiableAt ℂ f z 
goal: AnalyticAt ℂ f c ↔ ∀ᶠ (z : ℂ) in 𝓝 c, DifferentiableAt ℂ f z