mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Calculus.FDeriv.Symmetric

Goal state before:
pp: E : Type u_1
F : Type u_2
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
s : Set E
s_conv : Convex ℝ s
f : E → F
f' : E → E →L[ℝ] F
f'' : E →L[ℝ] E →L[ℝ] F
hf : ∀ x ∈ interior s, HasFDerivAt f (f' x) x
x : E
xs : x ∈ s
hx : HasFDerivWithinAt f' f'' (interior s) x
v w : E
h4v : x + 4 • v ∈ interior s
h4w : x + 4 • w ∈ interior s
⊢ (fun h ↦
      f (x + h • (2 • v + 2 • w)) + f (x + h • (v + w)) - f (x + h • (2 • v + w)) - f (x + h • (v + 2 • w)) -
        h ^ 2 • (f'' v) w) =o[𝓝[>] 0]
    fun h ↦ h ^ 2

Tactic:
have A : (1 : ℝ) / 2 ∈ Ioc (0 : ℝ) 1 := ⟨by simp, by norm_num⟩
  have B : (1 : ℝ) / 2 ∈ Icc (0 : ℝ) 1 := ⟨by simp, by norm_num⟩
  have h2v2w : x + (2 : ℝ) • v + (2 : ℝ) • w ∈ interior s := by
    convert! s_conv.interior.add_smul_sub_mem h4v h4w B using 1
    module
  have h2vww : x + (2 • v + w) + w ∈ interior s := by
    convert! h2v2w using 1
    module
  have h2v : x + (2 : ℝ) • v ∈ interior s := by
    convert! s_conv.add_smul_sub_mem_interior xs h4v A using 1
    module
  have h2w : x + (2 : ℝ) • w ∈ interior s := by
    convert! s_conv.add_smul_sub_mem_interior xs h4w A using 1
    module
  have hvw : x + (v + w) ∈ interior s := by
    convert! s_conv.add_smul_sub_mem_interior xs h2v2w A using 1
    module
  have h2vw : x + (2 • v + w) ∈ interior s := by
    convert! s_conv.interior.add_smul_sub_mem h2v h2v2w B using 1
    module
  have hvww : x + (v + w) + w ∈ interior s := by
    convert! s_conv.interior.add_smul_sub_mem h2w h2v2w B using 1
    module
  have TA1 := s_conv.taylor_approx_two_segment hf xs hx h2vw h2vww
  have TA2 := s_conv.taylor_approx_two_segment hf xs hx hvw hvww
  convert! TA1.sub TA2 using 1
  ext h
  simp only [two_smul, smul_add, ← add_assoc, map_add,
    add_apply]
  abel

Goal state after:
Module: Mathlib.MeasureTheory.Covering.Besicovitch

Goal state before:
pp: α : Type u_1
inst✝⁶ : MetricSpace α
inst✝⁵ : SecondCountableTopology α
inst✝⁴ : MeasurableSpace α
inst✝³ : OpensMeasurableSpace α
inst✝² : HasBesicovitchCovering α
μ : Measure α
inst✝¹ : SFinite μ
inst✝ : μ.OuterRegular
ε : ℝ≥0∞
hε : ε ≠ 0
f : α → Set ℝ
s : Set α
hf : ∀ x ∈ s, ∀ δ > 0, (f x ∩ Ioo 0 δ).Nonempty
u : Set α
su : u ⊇ s
u_open : IsOpen[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] u
μu : μ u ≤ μ s + ε / 2
R : α → ℝ
hR : ∀ x ∈ s, R x > 0 ∧ ball x (R x) ⊆ u
t0 : Set α
r0 : α → ℝ
t0_count : t0.Countable
t0s : t0 ⊆ s
hr0 : ∀ x ∈ t0, r0 x ∈ f x ∩ Ioo 0 (R x)
μt0 : μ (s \ ⋃ x ∈ t0, closedBall x (r0 x)) = 0
t0_disj : t0.PairwiseDisjoint fun x ↦ closedBall x (r0 x)
s' : Set α := s \ ⋃ x ∈ t0, closedBall x (r0 x)
s's : s' ⊆ s
N : ℕ
τ : ℝ
hτ : 1 < τ
H : IsEmpty (SatelliteConfig α N τ)
v : Set α
s'v : v ⊇ s'
v_open : IsOpen[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] v
μv : μ v ≤ μ s' + ε / 2 / ↑N
r1 : α → ℝ
hr1 : ∀ x ∈ s', r1 x ∈ f x ∩ Ioo 0 1 ∧ closedBall x (r1 x) ⊆ v
q : BallPackage (↑s') α := { c := fun x ↦ ↑x, r := fun x ↦ r1 ↑x, rpos := ⋯, r_bound := 1, r_le := ⋯ }
S : Fin N → Set ↑s'
S_disj : ∀ (i : Fin N), (S i).PairwiseDisjoint fun j ↦ closedBall (q.c j) (q.r j)
hS : range q.c ⊆ ⋃ i, ⋃ j ∈ S i, ball (q.c j) (q.r j)
S_count : ∀ (i : Fin N), (S i).Countable
r : α → ℝ := fun x ↦ if x ∈ s' then r1 x else r0 x
r_t0 : ∀ x ∈ t0, r x = r0 x
A : ∑' (x : ↑t0), μ (closedBall (↑x) (r ↑x)) ≤ μ s + ε / 2
B : ∀ (i : Fin N), ∑' (x : ↑(Subtype.val '' S i)), μ (closedBall (↑x) (r ↑x)) ≤ ε / 2 / ↑N
⊢ μ s + ε / 2 + ε / 2 = μ s + ε

Tactic:
by rw [add_assoc, ENNReal.add_halves]

Goal state after:
Module: Mathlib.Analysis.Calculus.FDeriv.Symmetric

Goal state before:
pp: case pos
𝕜 : Type u_1
inst✝ : NontriviallyNormedField 𝕜
n : ℕ∞ω
h : IsRCLikeNormedField 𝕜
⊢ n = ∞ ↔ n = ∞ ∧ IsRCLikeNormedField 𝕜

Tactic:
simp [h]

Goal state after:
Module: Mathlib.Analysis.Calculus.FDeriv.Symmetric

Goal state before:
pp: case neg
𝕜 : Type u_1
inst✝ : NontriviallyNormedField 𝕜
n : ℕ∞ω
h : ¬IsRCLikeNormedField 𝕜
⊢ ω = ∞ ↔ n = ∞ ∧ IsRCLikeNormedField 𝕜

Tactic:
simp [h]

Goal state after:
Module: Mathlib.Analysis.Calculus.FDeriv.Symmetric

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁴ : NontriviallyNormedField 𝕜
E : Type u_2
F : Type u_3
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
f : E → F
x : E
n : ℕ∞ω
hf : ContDiffAt 𝕜 n f x
hn : minSmoothness 𝕜 2 ≤ n
⊢ IsSymmSndFDerivAt 𝕜 f x

Tactic:
by
  by_cases h : IsRCLikeNormedField 𝕜
  -- First deal with the `ℝ` or `ℂ` case, where `C^2` is enough.
  · intro v w
    apply second_derivative_symmetric_of_eventually (f := f) (f' := fderiv 𝕜 f) (x := x)
    · obtain ⟨u, hu, h'u⟩ : ∃ u ∈ 𝓝 x, ContDiffOn 𝕜 2 f u :=
        (hf.of_le hn).contDiffOn (m := 2) le_minSmoothness (by simp)
      rcases mem_nhds_iff.1 hu with ⟨v, vu, v_open, xv⟩
      filter_upwards [v_open.mem_nhds xv] with y hy
      have : DifferentiableAt 𝕜 f y := by
        have := (h'u.mono vu y hy).contDiffAt (v_open.mem_nhds hy)
        exact this.differentiableAt two_ne_zero
      exact DifferentiableAt.hasFDerivAt this
    · have : DifferentiableAt 𝕜 (fderiv 𝕜 f) x := by
        apply ContDiffAt.differentiableAt _ one_ne_zero
        exact hf.fderiv_right (le_minSmoothness.trans hn)
      exact DifferentiableAt.hasFDerivAt this
  -- then deal with the case of an arbitrary field, with analytic functions.
  · simp only [minSmoothness, h, ↓reduceIte, top_le_iff] at hn
    apply ContDiffAt.isSymmSndFDerivAt_of_omega
    simpa [hn] using hf

Goal state after:
Module: Mathlib.Analysis.Normed.Module.Complemented

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : CompleteSpace E
p q : Subspace 𝕜 E
h : IsCompl p q
hp : IsClosed ↑p
hq : IsClosed ↑q
⊢ IsTopCompl p q

Tactic:
have := hp.completeSpace_coe

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : CompleteSpace E
p q : Subspace 𝕜 E
h : IsCompl p q
hp : IsClosed ↑p
hq : IsClosed ↑q
this : CompleteSpace ↑↑p
⊢ IsTopCompl p q
Module: Mathlib.Analysis.Calculus.Implicit

Goal state before:
pp: case e'_13
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ 0 =
    (implicitFunctionDataOfComplemented f f' hf hf' hker).rightFun
      (implicitFunctionDataOfComplemented f f' hf hf' hker).pt

pp: case convert_1
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ (implicitFunctionDataOfComplemented f f' hf hf' hker).rightDeriv ∘SL (↑f').ker.subtypeL =
    ContinuousLinearMap.id 𝕜 ↥(↑f').ker

pp: case convert_2
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ (implicitFunctionDataOfComplemented f f' hf hf' hker).leftDeriv ∘SL (↑f').ker.subtypeL = 0

Tactic:
swap

Goal state after:
case convert_1
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ (implicitFunctionDataOfComplemented f f' hf hf' hker).rightDeriv ∘SL (↑f').ker.subtypeL =
    ContinuousLinearMap.id 𝕜 ↥(↑f').ker

case e'_13
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ 0 =
    (implicitFunctionDataOfComplemented f f' hf hf' hker).rightFun
      (implicitFunctionDataOfComplemented f f' hf hf' hker).pt

case convert_2
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ (implicitFunctionDataOfComplemented f f' hf hf' hker).leftDeriv ∘SL (↑f').ker.subtypeL = 0
Module: Mathlib.Analysis.Calculus.Implicit

Goal state before:
pp: case e'_13
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ 0 =
    (implicitFunctionDataOfComplemented f f' hf hf' hker).rightFun
      (implicitFunctionDataOfComplemented f f' hf hf' hker).pt

pp: case convert_2
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ (implicitFunctionDataOfComplemented f f' hf hf' hker).leftDeriv ∘SL (↑f').ker.subtypeL = 0

Tactic:
swap

Goal state after:
case convert_2
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ (implicitFunctionDataOfComplemented f f' hf hf' hker).leftDeriv ∘SL (↑f').ker.subtypeL = 0

case e'_13
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : CompleteSpace E
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : CompleteSpace F
f : E → F
f' : E →L[𝕜] F
a : E
hf : HasStrictFDerivAt f f' a
hf' : (↑f').range = ⊤
hker : (↑f').ker.ClosedComplemented
⊢ 0 =
    (implicitFunctionDataOfComplemented f f' hf hf' hker).rightFun
      (implicitFunctionDataOfComplemented f f' hf hf' hker).pt
Module: Mathlib.Analysis.Calculus.LHopital

Goal state before:
pp: case refine_2
a b : ℝ
l : Filter ℝ
f f' g g' : ℝ → ℝ
hab : a < b
hff' : ∀ x ∈ Ioo a b, HasDerivAt f (f' x) x
hgg' : ∀ x ∈ Ioo a b, HasDerivAt g (g' x) x
hcf : ContinuousOn f (Ico a b)
hcg : ContinuousOn g (Ico a b)
hg' : ∀ x ∈ Ioo a b, g' x ≠ 0
hfa : f a = 0
hga : g a = 0
hdiv : Tendsto (fun x ↦ f' x / g' x) (𝓝[>] a) l
⊢ Tendsto g (𝓝[Ioo a b] a) (𝓝 (g a))

Tactic:
exact ((hcg a <| left_mem_Ico.mpr hab).mono Ioo_subset_Ico_self).tendsto

Goal state after:
Module: Mathlib.Analysis.Calculus.LHopital

Goal state before:
pp: case refine_1
a b : ℝ
l : Filter ℝ
f f' g g' : ℝ → ℝ
hab : a < b
hff' : ∀ x ∈ Ioo a b, HasDerivAt f (f' x) x
hgg' : ∀ x ∈ Ioo a b, HasDerivAt g (g' x) x
hcf : ContinuousOn f (Ioc a b)
hcg : ContinuousOn g (Ioc a b)
hg' : ∀ x ∈ Ioo a b, g' x ≠ 0
hfb : f b = 0
hgb : g b = 0
hdiv : Tendsto (fun x ↦ f' x / g' x) (𝓝[<] b) l
⊢ Tendsto f (𝓝[<] b) (𝓝 0)

Tactic:
rw [← hfb, ← nhdsWithin_Ioo_eq_nhdsLT hab]

Goal state after:
case refine_1
a b : ℝ
l : Filter ℝ
f f' g g' : ℝ → ℝ
hab : a < b
hff' : ∀ x ∈ Ioo a b, HasDerivAt f (f' x) x
hgg' : ∀ x ∈ Ioo a b, HasDerivAt g (g' x) x
hcf : ContinuousOn f (Ioc a b)
hcg : ContinuousOn g (Ioc a b)
hg' : ∀ x ∈ Ioo a b, g' x ≠ 0
hfb : f b = 0
hgb : g b = 0
hdiv : Tendsto (fun x ↦ f' x / g' x) (𝓝[<] b) l
⊢ Tendsto f (𝓝[Ioo a b] b) (𝓝 (f b))
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.IntegrationByParts

Goal state before:
pp: case pos
a b : ℝ
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f f' : ℝ → ℝ
g : ℝ → E
hf : ContinuousOn f [[a, b]]
hff' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt f (f' x) (Ioi x) x
hg_cont : ContinuousOn g (f '' Ioo (min a b) (max a b))
hg1 : IntegrableOn g (f '' [[a, b]]) volume
hg2 : IntegrableOn (fun x ↦ f' x • (g ∘ f) x) [[a, b]] volume
hE : CompleteSpace E
⊢ ∫ (x : ℝ) in a..b, f' x • (g ∘ f) x = ∫ (u : ℝ) in f a..f b, g u

pp: case neg
a b : ℝ
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f f' : ℝ → ℝ
g : ℝ → E
hf : ContinuousOn f [[a, b]]
hff' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt f (f' x) (Ioi x) x
hg_cont : ContinuousOn g (f '' Ioo (min a b) (max a b))
hg1 : IntegrableOn g (f '' [[a, b]]) volume
hg2 : IntegrableOn (fun x ↦ f' x • (g ∘ f) x) [[a, b]] volume
hE : ¬CompleteSpace E
⊢ ∫ (x : ℝ) in a..b, f' x • (g ∘ f) x = ∫ (u : ℝ) in f a..f b, g u

Tactic:
swap

Goal state after:
case neg
a b : ℝ
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f f' : ℝ → ℝ
g : ℝ → E
hf : ContinuousOn f [[a, b]]
hff' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt f (f' x) (Ioi x) x
hg_cont : ContinuousOn g (f '' Ioo (min a b) (max a b))
hg1 : IntegrableOn g (f '' [[a, b]]) volume
hg2 : IntegrableOn (fun x ↦ f' x • (g ∘ f) x) [[a, b]] volume
hE : ¬CompleteSpace E
⊢ ∫ (x : ℝ) in a..b, f' x • (g ∘ f) x = ∫ (u : ℝ) in f a..f b, g u

case pos
a b : ℝ
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f f' : ℝ → ℝ
g : ℝ → E
hf : ContinuousOn f [[a, b]]
hff' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt f (f' x) (Ioi x) x
hg_cont : ContinuousOn g (f '' Ioo (min a b) (max a b))
hg1 : IntegrableOn g (f '' [[a, b]]) volume
hg2 : IntegrableOn (fun x ↦ f' x • (g ∘ f) x) [[a, b]] volume
hE : CompleteSpace E
⊢ ∫ (x : ℝ) in a..b, f' x • (g ∘ f) x = ∫ (u : ℝ) in f a..f b, g u
Module: Mathlib.Analysis.Calculus.LHopital

Goal state before:
pp: case refine_2
a b : ℝ
l : Filter ℝ
f g : ℝ → ℝ
hab : a < b
hdf : DifferentiableOn ℝ f (Ioo a b)
hcf : ContinuousOn f (Ico a b)
hcg : ContinuousOn g (Ico a b)
hg' : ∀ x ∈ Ioo a b, deriv g x ≠ 0
hfa : f a = 0
hga : g a = 0
hdiv : Tendsto (fun x ↦ deriv f x / deriv g x) (𝓝[>] a) l
⊢ Tendsto g (𝓝[Ioo a b] a) (𝓝 (g a))

Tactic:
exact ((hcg a <| left_mem_Ico.mpr hab).mono Ioo_subset_Ico_self).tendsto

Goal state after:
Module: Mathlib.MeasureTheory.Function.JacobianOneDim

Goal state before:
pp: case pos
F : Type u_1
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
s : Set ℝ
f f' : ℝ → ℝ
hs : MeasurableSet s
hf' : ∀ x ∈ s, HasDerivWithinAt f (f' x) s x
hf : MonotoneOn f s
g : ℝ → F
H : IntegrableOn g (f '' s) volume
⊢ ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in s, f' x • g (f x)

pp: case neg
F : Type u_1
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
s : Set ℝ
f f' : ℝ → ℝ
hs : MeasurableSet s
hf' : ∀ x ∈ s, HasDerivWithinAt f (f' x) s x
hf : MonotoneOn f s
g : ℝ → F
H : ¬IntegrableOn g (f '' s) volume
⊢ ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in s, f' x • g (f x)

Tactic:
swap

Goal state after:
case neg
F : Type u_1
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
s : Set ℝ
f f' : ℝ → ℝ
hs : MeasurableSet s
hf' : ∀ x ∈ s, HasDerivWithinAt f (f' x) s x
hf : MonotoneOn f s
g : ℝ → F
H : ¬IntegrableOn g (f '' s) volume
⊢ ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in s, f' x • g (f x)

case pos
F : Type u_1
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
s : Set ℝ
f f' : ℝ → ℝ
hs : MeasurableSet s
hf' : ∀ x ∈ s, HasDerivWithinAt f (f' x) s x
hf : MonotoneOn f s
g : ℝ → F
H : IntegrableOn g (f '' s) volume
⊢ ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in s, f' x • g (f x)
Module: Mathlib.MeasureTheory.Function.Jacobian

Goal state before:
pp: E : Type u_1
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : FiniteDimensional ℝ E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : μ.IsAddHaarMeasure
A : E →L[ℝ] E
m : ℝ≥0
hm : ENNReal.ofReal |A.det| < ↑m
d : ℝ≥0∞ := ENNReal.ofReal |A.det|
ε : ℝ
hε : μ (closedBall 0 ε + ⇑A '' closedBall 0 1) < ↑m * μ (closedBall 0 1)
εpos : 0 < ε
this✝ : Iio (NNReal.mk ε ⋯) ∈ 𝓝 0
δ : ℝ≥0
s : Set E
f : E → E
hf : ApproximatesLinearOn f A s δ
hδ : ↑δ < ε
x : E
r : ℝ
xs : x ∈ s
r0 : 0 ≤ r
K : f '' (s ∩ closedBall x r) ⊆ {f x} + r • (⇑A '' closedBall 0 1 + closedBall 0 ε)
this : ⇑A '' closedBall 0 r + closedBall (f x) (ε * r) = {f x} + r • (⇑A '' closedBall 0 1 + closedBall 0 ε)
⊢ ENNReal.ofReal (r ^ finrank ℝ E) * (↑m * μ (closedBall 0 1)) = ↑m * μ (closedBall x r)

Tactic:
simp only [addHaar_closedBall' μ _ r0]; ring

Goal state after:
Module: Mathlib.MeasureTheory.Integral.IntegralEqImproper

Goal state before:
pp: ι : Type u_1
E : Type u_2
μ : Measure ℝ
l : Filter ι
inst✝² : l.IsCountablyGenerated
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
b : ι → ℝ
f : ℝ → E
hb : Tendsto b l atTop
⊢ Tendsto (fun i ↦ ∫ (x : ℝ) in Ioi (b i), f x ∂μ) l (𝓝 0)

Tactic:
by_cases! h : ∀ a, ¬ IntegrableOn f (Ioi a) μ
  · exact tendsto_const_nhds.congr (fun i => (integral_undef (h (b i))).symm)
  obtain ⟨a, ha⟩ := h
  have : ∀ᶠ i in l, ∫ x in Ioi a, f x ∂μ - ∫ x in a..b i, f x ∂μ = ∫ x in Ioi (b i), f x ∂μ := by
    filter_upwards [hb.eventually_mem (Ici_mem_atTop a)] with i hi
    rw [sub_eq_iff_eq_add',
      intervalIntegral.integral_interval_add_Ioi ha (ha.mono_set (Ioi_subset_Ioi hi))]
  rw [← sub_self (∫ x in Ioi a, f x ∂μ)]
  exact Tendsto.congr' this (Tendsto.const_sub _ <| intervalIntegral_tendsto_integral_Ioi a ha hb)

Goal state after:
Module: Mathlib.MeasureTheory.Function.Jacobian

Goal state before:
pp: E : Type u_1
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : FiniteDimensional ℝ E
s : Set E
f : E → E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : μ.IsAddHaarMeasure
A : E →L[ℝ] E
δ : ℝ≥0
hf : ApproximatesLinearOn f A s δ
hs : MeasurableSet s
f' : E → E →L[ℝ] E
hf' : ∀ x ∈ s, HasFDerivWithinAt f (f' x) s x
x : E
hx : Tendsto (fun r ↦ μ (s ∩ closedBall x r) / μ (closedBall x r)) (𝓝[>] 0) (𝓝 1)
xs : x ∈ s
z : E
ε : ℝ
εpos : 0 < ε
B₁ : ∀ᶠ (r : ℝ) in 𝓝[>] 0, (s ∩ ({x} + r • closedBall z ε)).Nonempty
ρ : ℝ
ρpos : ρ > 0
hρ : ball x ρ ∩ s ⊆ {y | ‖f y - f x - (f' x) (y - x)‖ ≤ ε * ‖y - x‖}
B₂ : ∀ᶠ (r : ℝ) in 𝓝[>] 0, {x} + r • closedBall z ε ⊆ ball x ρ
r : ℝ
y : E
ys : y ∈ s
hy : y ∈ {x} + r • closedBall z ε
rρ : {x} + r • closedBall z ε ⊆ ball x ρ
rpos : 0 < r
a : E
az : a ∈ closedBall z ε
ya : y = x + r • a
norm_a : ‖a‖ ≤ ‖z‖ + ε
⊢ ↑δ * ‖y - x‖ + ε * ‖y - x‖ = r * (↑δ + ε) * ‖a‖

Tactic:
simp only [ya, add_sub_cancel_left, norm_smul, Real.norm_eq_abs, abs_of_nonneg rpos.le]
        ring

Goal state after:
Module: Mathlib.MeasureTheory.Integral.IntegralEqImproper

Goal state before:
pp: case pos
E : Type u_1
f f' : ℝ → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hderiv : ∀ (x : ℝ), HasDerivAt f (f' x) x
hf' : Integrable f' volume
hf : Integrable f volume
hE : CompleteSpace E
⊢ ∫ (x : ℝ), f' x = 0

pp: case neg
E : Type u_1
f f' : ℝ → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hderiv : ∀ (x : ℝ), HasDerivAt f (f' x) x
hf' : Integrable f' volume
hf : Integrable f volume
hE : ¬CompleteSpace E
⊢ ∫ (x : ℝ), f' x = 0

Tactic:
swap

Goal state after:
case neg
E : Type u_1
f f' : ℝ → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hderiv : ∀ (x : ℝ), HasDerivAt f (f' x) x
hf' : Integrable f' volume
hf : Integrable f volume
hE : ¬CompleteSpace E
⊢ ∫ (x : ℝ), f' x = 0

case pos
E : Type u_1
f f' : ℝ → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hderiv : ∀ (x : ℝ), HasDerivAt f (f' x) x
hf' : Integrable f' volume
hf : Integrable f volume
hE : CompleteSpace E
⊢ ∫ (x : ℝ), f' x = 0
Module: Mathlib.Analysis.Complex.RemovableSingularity

Goal state before:
pp: case inl
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
s : Set ℂ
x : ℂ
hx : x ∈ s
hs : s ∈ 𝓝 x
hd : DifferentiableOn ℂ f (s \ {x})
hc : ContinuousAt f x
⊢ ∀ᶠ (z : ℂ) in 𝓝[≠] x, DifferentiableAt ℂ f z

Tactic:
refine eventually_nhdsWithin_iff.2 ((eventually_mem_nhds_iff.2 hs).mono fun z hz hzx => ?_)

Goal state after:
case inl
E : Type u
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
s : Set ℂ
x : ℂ
hx : x ∈ s
hs : s ∈ 𝓝 x
hd : DifferentiableOn ℂ f (s \ {x})
hc : ContinuousAt f x
z : ℂ
hz : s ∈ 𝓝 z
hzx : z ∈ {x}ᶜ
⊢ DifferentiableAt ℂ f z
Module: Mathlib.MeasureTheory.Function.Jacobian

Goal state before:
pp: case hn
E : Type u_1
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : FiniteDimensional ℝ E
s : Set E
f : E → E
f' : E → E →L[ℝ] E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : μ.IsAddHaarMeasure
hf' : ∀ x ∈ s, HasFDerivWithinAt f (f' x) s x
R : ℝ
hs : s ⊆ closedBall 0 R
ε : ℝ≥0
εpos : 0 < ε
h'f' : ∀ x ∈ s, (f' x).det = 0
h's : s.Nonempty
δ : (E →L[ℝ] E) → ℝ≥0
hδ :
  ∀ (A : E →L[ℝ] E),
    0 < δ A ∧ ∀ (t : Set E), ApproximatesLinearOn f A t (δ A) → μ (f '' t) ≤ ↑(|A.det|.toNNReal + ε) * μ t
t : ℕ → Set E
A : ℕ → E →L[ℝ] E
t_disj : Pairwise (Disjoint on t)
t_meas : ∀ (n : ℕ), MeasurableSet (t n)
t_cover : s ⊆ ⋃ n, t n
ht : ∀ (n : ℕ), ApproximatesLinearOn f (A n) (s ∩ t n) (δ (A n))
Af' : s.Nonempty → ∀ (n : ℕ), ∃ y ∈ s, A n = f' y
⊢ Pairwise (Disjoint on fun n ↦ closedBall 0 R ∩ t n)

Tactic:
exact pairwise_disjoint_mono t_disj fun n => inter_subset_right

Goal state after: