l3lab/ntp-mathlib huggingface dataset:
/-- 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 := by
  set e : (ℝ × ℝ) ≃L[ℝ] ℂ := equivRealProdClm.symm
  have he : ∀ x y : ℝ, ↑x + ↑y * I = e (x, y) := fun x y => (mk_eq_add_mul_I x y).symm
  have he₁ : e (1, 0) = 1 := rfl; have he₂ : e (0, 1) = I := rfl
  simp only [he] at *
  set F : ℝ × ℝ → E := f ∘ e
  set F' : ℝ × ℝ → ℝ × ℝ →L[ℝ] E := fun p => (f' (e p)).comp (e : ℝ × ℝ →L[ℝ] ℂ)
  have hF' : ∀ p : ℝ × ℝ, (-(I • F' p)) (1, 0) + F' p (0, 1) = -(I • f' (e p) 1 - f' (e p) I) := by
    rintro ⟨x, y⟩
    

Proof state:
case mk
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
f' : ℂ → ℂ →L[ℝ] E
z w : ℂ
s : Set ℂ
hs : Set.Countable s
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]])
e : (ℝ × ℝ) ≃L[ℝ] ℂ := ContinuousLinearEquiv.symm equivRealProdClm
he₁ : (ContinuousLinearEquiv.symm equivRealProdClm) (1, 0) = 1
he₂ : (ContinuousLinearEquiv.symm equivRealProdClm) (0, 1) = I
he : ℝ → ℝ → True
F : ℝ × ℝ → E := f ∘ ⇑e
F' : ℝ × ℝ → ℝ × ℝ →L[ℝ] E := fun p => ContinuousLinearMap.comp (f' (e p)) ↑e
x y : ℝ
⊢ (-(I • F' (x, y))) (1, 0) + (F' (x, y)) (0, 1) = -(I • (f' (e (x, y))) 1 - (f' (e (x, y))) I)

Next tactic:
simp only [ContinuousLinearMap.neg_apply, ContinuousLinearMap.smul_apply,
      ContinuousLinearMap.comp_apply, ContinuousLinearEquiv.coe_coe, he₁, he₂, neg_add_eq_sub,
      neg_sub]
/-- 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 :=
  integral_boundary_rect_of_hasFDerivAt_real_off_countable f (fderiv ℝ f) z w ∅ countable_empty
    Hd.continuousOn
    (fun x hx => Hd.hasFDerivAt <| by
      

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
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 : ℂ
hx : x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im) \ ∅
⊢ [[z.re, w.re]] ×ℂ [[z.im, w.im]] ∈ 𝓝 x

Next tactic:
simpa only [← mem_interior_iff_mem_nhds, interior_reProdIm, uIcc, interior_Icc] using hx.1
/-- **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 := by
  -- porting note: `simp` fails to use `ContinuousLinearMap.coe_restrictScalars'`
  

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
z w : ℂ
s : Set ℂ
hs : Set.Countable s
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 (↑w.re + ↑y * I)) -
      I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * I) =
    0

Next tactic:
have : ∀ z, I • (fderiv ℂ f z).restrictScalars ℝ 1 = (fderiv ℂ f z).restrictScalars ℝ I := fun z ↦
    by rw [(fderiv ℂ f _).coe_restrictScalars', ← (fderiv ℂ f _).map_smul, smul_eq_mul, mul_one]
/-- **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 := by
  -- porting note: `simp` fails to use `ContinuousLinearMap.coe_restrictScalars'`
  have : ∀ z, I • (fderiv ℂ f z).restrictScalars ℝ 1 = (fderiv ℂ f z).restrictScalars ℝ I := fun z ↦
    by 

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
z✝ w : ℂ
s : Set ℂ
hs : Set.Countable s
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
z : ℂ
⊢ I • (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) 1 =
    (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) I

Next tactic:
rw [(fderiv ℂ f _).coe_restrictScalars', ← (fderiv ℂ f _).map_smul, smul_eq_mul, mul_one]
/-- **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 := by
  -- porting note: `simp` fails to use `ContinuousLinearMap.coe_restrictScalars'`
  have : ∀ z, I • (fderiv ℂ f z).restrictScalars ℝ 1 = (fderiv ℂ f z).restrictScalars ℝ I := fun z ↦
    by rw [(fderiv ℂ f _).coe_restrictScalars', ← (fderiv ℂ f _).map_smul, smul_eq_mul, mul_one]
  

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
z w : ℂ
s : Set ℂ
hs : Set.Countable s
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
this :
  ∀ (z : ℂ),
    I • (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) 1 =
      (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) I
⊢ (((∫ (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 (↑w.re + ↑y * I)) -
      I • ∫ (y : ℝ) in z.im..w.im, f (↑z.re + ↑y * I) =
    0

Next tactic:
refine (integral_boundary_rect_of_hasFDerivAt_real_off_countable f
    (fun z => (fderiv ℂ f z).restrictScalars ℝ) z w s hs Hc
    (fun x hx => (Hd x hx).hasFDerivAt.restrictScalars ℝ) ?_).trans ?_
/-- **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 := by
  -- porting note: `simp` fails to use `ContinuousLinearMap.coe_restrictScalars'`
  have : ∀ z, I • (fderiv ℂ f z).restrictScalars ℝ 1 = (fderiv ℂ f z).restrictScalars ℝ I := fun z ↦
    by rw [(fderiv ℂ f _).coe_restrictScalars', ← (fderiv ℂ f _).map_smul, smul_eq_mul, mul_one]
  refine (integral_boundary_rect_of_hasFDerivAt_real_off_countable f
    (fun z => (fderiv ℂ f z).restrictScalars ℝ) z w s hs Hc
    (fun x hx => (Hd x hx).hasFDerivAt.restrictScalars ℝ) ?_).trans ?_ <;> 

Proof state:
case refine_1
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
z w : ℂ
s : Set ℂ
hs : Set.Countable s
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
this :
  ∀ (z : ℂ),
    I • (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) 1 =
      (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) I
⊢ IntegrableOn
    (fun z =>
      I • ((fun z => ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) z) 1 -
        ((fun z => ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) z) I)
    ([[z.re, w.re]] ×ℂ [[z.im, w.im]])

Next tactic:
simp [this]
/-- **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 := by
  -- porting note: `simp` fails to use `ContinuousLinearMap.coe_restrictScalars'`
  have : ∀ z, I • (fderiv ℂ f z).restrictScalars ℝ 1 = (fderiv ℂ f z).restrictScalars ℝ I := fun z ↦
    by rw [(fderiv ℂ f _).coe_restrictScalars', ← (fderiv ℂ f _).map_smul, smul_eq_mul, mul_one]
  refine (integral_boundary_rect_of_hasFDerivAt_real_off_countable f
    (fun z => (fderiv ℂ f z).restrictScalars ℝ) z w s hs Hc
    (fun x hx => (Hd x hx).hasFDerivAt.restrictScalars ℝ) ?_).trans ?_ <;> 

Proof state:
case refine_2
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
z w : ℂ
s : Set ℂ
hs : Set.Countable s
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
this :
  ∀ (z : ℂ),
    I • (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) 1 =
      (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f z)) I
⊢ ∫ (x : ℝ) in z.re..w.re,
      ∫ (y : ℝ) in z.im..w.im,
        I • (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f (↑x + ↑y * I))) 1 -
          (ContinuousLinearMap.restrictScalars ℝ (fderiv ℂ f (↑x + ↑y * I))) I =
    0

Next tactic:
simp [this]
/-- If `f : ℂ → E` is continuous 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 := by
  /- We apply the previous lemma to `fun z ↦ f (c + exp z)` on the rectangle
    `[log r, log R] × [0, 2 * π]`. -/
  

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
r R : ℝ
h0 : 0 < r
hle : r ≤ R
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
hc : ContinuousOn f (closedBall c R \ ball c r)
hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z
⊢ (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, r), (z - c)⁻¹ • f z

Next tactic:
set A := closedBall c R \ ball c r
/-- If `f : ℂ → E` is continuous 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 := by
  /- We apply the previous lemma to `fun z ↦ f (c + exp z)` on the rectangle
    `[log r, log R] × [0, 2 * π]`. -/
  set A := closedBall c R \ ball c r
  

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
r R : ℝ
h0 : 0 < r
hle : r ≤ R
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c R \ ball c r
hc : ContinuousOn f A
⊢ (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, r), (z - c)⁻¹ • f z

Next tactic:
obtain ⟨a, rfl⟩ : ∃ a, Real.exp a = r
/-- If `f : ℂ → E` is continuous 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 := by
  /- We apply the previous lemma to `fun z ↦ f (c + exp z)` on the rectangle
    `[log r, log R] × [0, 2 * π]`. -/
  set A := closedBall c R \ ball c r
  obtain ⟨a, rfl⟩ : ∃ a, Real.exp a = r; 

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
r R : ℝ
h0 : 0 < r
hle : r ≤ R
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c R \ ball c r
hc : ContinuousOn f A
⊢ ∃ a, rexp a = r
case intro
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
R : ℝ
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
a : ℝ
h0 : 0 < rexp a
hle : rexp a ≤ R
hd : ∀ z ∈ (ball c R \ closedBall c (rexp a)) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c R \ ball c (rexp a)
hc : ContinuousOn f A
⊢ (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, rexp a), (z - c)⁻¹ • f z

Next tactic:
exact ⟨Real.log r, Real.exp_log h0⟩
/-- If `f : ℂ → E` is continuous 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 := by
  /- We apply the previous lemma to `fun z ↦ f (c + exp z)` on the rectangle
    `[log r, log R] × [0, 2 * π]`. -/
  set A := closedBall c R \ ball c r
  obtain ⟨a, rfl⟩ : ∃ a, Real.exp a = r; exact ⟨Real.log r, Real.exp_log h0⟩
  

Proof state:
case intro
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
R : ℝ
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
a : ℝ
h0 : 0 < rexp a
hle : rexp a ≤ R
hd : ∀ z ∈ (ball c R \ closedBall c (rexp a)) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c R \ ball c (rexp a)
hc : ContinuousOn f A
⊢ (∮ (z : ℂ) in C(c, R), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, rexp a), (z - c)⁻¹ • f z

Next tactic:
obtain ⟨b, rfl⟩ : ∃ b, Real.exp b = R
/-- If `f : ℂ → E` is continuous 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 := by
  /- We apply the previous lemma to `fun z ↦ f (c + exp z)` on the rectangle
    `[log r, log R] × [0, 2 * π]`. -/
  set A := closedBall c R \ ball c r
  obtain ⟨a, rfl⟩ : ∃ a, Real.exp a = r; exact ⟨Real.log r, Real.exp_log h0⟩
  obtain ⟨b, rfl⟩ : ∃ b, Real.exp b = R; 

Proof state:
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
R : ℝ
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
a : ℝ
h0 : 0 < rexp a
hle : rexp a ≤ R
hd : ∀ z ∈ (ball c R \ closedBall c (rexp a)) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c R \ ball c (rexp a)
hc : ContinuousOn f A
⊢ ∃ b, rexp b = R
case intro.intro
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
a : ℝ
h0 : 0 < rexp a
b : ℝ
hle : rexp a ≤ rexp b
hd : ∀ z ∈ (ball c (rexp b) \ closedBall c (rexp a)) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c (rexp b) \ ball c (rexp a)
hc : ContinuousOn f A
⊢ (∮ (z : ℂ) in C(c, rexp b), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, rexp a), (z - c)⁻¹ • f z

Next tactic:
exact ⟨Real.log R, Real.exp_log (h0.trans_le hle)⟩
/-- If `f : ℂ → E` is continuous 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 := by
  /- We apply the previous lemma to `fun z ↦ f (c + exp z)` on the rectangle
    `[log r, log R] × [0, 2 * π]`. -/
  set A := closedBall c R \ ball c r
  obtain ⟨a, rfl⟩ : ∃ a, Real.exp a = r; exact ⟨Real.log r, Real.exp_log h0⟩
  obtain ⟨b, rfl⟩ : ∃ b, Real.exp b = R; exact ⟨Real.log R, Real.exp_log (h0.trans_le hle)⟩
  

Proof state:
case intro.intro
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
c : ℂ
f : ℂ → E
s : Set ℂ
hs : Set.Countable s
a : ℝ
h0 : 0 < rexp a
b : ℝ
hle : rexp a ≤ rexp b
hd : ∀ z ∈ (ball c (rexp b) \ closedBall c (rexp a)) \ s, DifferentiableAt ℂ f z
A : Set ℂ := closedBall c (rexp b) \ ball c (rexp a)
hc : ContinuousOn f A
⊢ (∮ (z : ℂ) in C(c, rexp b), (z - c)⁻¹ • f z) = ∮ (z : ℂ) in C(c, rexp a), (z - c)⁻¹ • f z

Next tactic:
rw [Real.exp_le_exp] at hle