mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Analytic.IsolatedZeros

Goal state before:
pp: 𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
x : 𝕜
f : 𝕜 → E
s : Set E
hfx : AnalyticAt 𝕜 f x
h₂f : ¬EventuallyConst f (𝓝 x)
hs : s ∈ 𝓝[≠] f x
⊢ f ⁻¹' s ∈ 𝓝[≠] x

Tactic:
have : ∀ᶠ (z : 𝕜) in 𝓝 x, f z ∈ insert (f x) s := by
    filter_upwards [hfx.continuousAt.preimage_mem_nhds (insert_mem_nhds_iff.2 hs)]
    tauto

Goal state after:
𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
x : 𝕜
f : 𝕜 → E
s : Set E
hfx : AnalyticAt 𝕜 f x
h₂f : ¬EventuallyConst f (𝓝 x)
hs : s ∈ 𝓝[≠] f x
this : ∀ᶠ (z : 𝕜) in 𝓝 x, f z ∈ insert (f x) s
⊢ f ⁻¹' s ∈ 𝓝[≠] x
Module: Mathlib.Analysis.Calculus.MeanValue

Goal state before:
pp: case hB'
f : ℝ → ℝ
a b : ℝ
hf : ContinuousOn f (Icc a b)
B B' : ℝ → ℝ
ha : f a ≤ B a
hB : ContinuousOn B (Icc a b)
hB' : ∀ x ∈ Ico a b, HasDerivWithinAt B (B' x) (Ici x) x
bound : ∀ x ∈ Ico a b, ∀ (r : ℝ), B' x < r → ∃ᶠ (z : ℝ) in 𝓝[>] x, slope f x z < r
x : ℝ
hx : x ∈ Icc a b
r : ℝ
hr : r > 0
⊢ ∀ x ∈ Ico a b, HasDerivWithinAt (fun x ↦ B x + r * (x - a)) (?m.110 x) (Ici x) x

Tactic:
intro x hx
      exact (hB' x hx).add (((hasDerivWithinAt_id x (Ici x)).sub_const a).const_mul r)

Goal state after:
Module: Mathlib.Analysis.Calculus.ContDiff.Defs

Goal state before:
pp: case mpr.refine_2.refine_1
𝕜 : Type u
inst✝⁴ : NontriviallyNormedField 𝕜
E : Type uE
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
F : Type uF
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
s : Set E
f : E → F
x : E
n : ℕ∞ω
hn : n ≠ ∞
h'n : n + 1 ≠ ∞
u : Set E
hu : u ∈ 𝓝[insert x s] x
hf : n = ω → AnalyticOn 𝕜 f u
f' : E → E →L[𝕜] F
f'_eq_deriv : ∀ x ∈ u, HasFDerivWithinAt f (f' x) u x
Hf' : ContDiffWithinAt 𝕜 n f' u x
v : Set E
hv : v ∈ 𝓝[insert x u] x
p' : E → FormalMultilinearSeries 𝕜 E (E →L[𝕜] F)
Hp' : HasFTaylorSeriesUpToOn n f' p' v
p'_an : n = ω → ∀ (i : ℕ), AnalyticOn 𝕜 (fun x ↦ p' x i) v
y : E
hy : y ∈ v ∩ u
⊢ HasFDerivWithinAt f (↑↑(continuousMultilinearCurryFin0 𝕜 E F).symm.symm ∘SL ((p' y).unshift (f y) 1).curryLeft)
    (v ∩ u) y

Tactic:
convert! (f'_eq_deriv y hy.2).mono inter_subset_right

Goal state after:
case e'_12
𝕜 : Type u
inst✝⁴ : NontriviallyNormedField 𝕜
E : Type uE
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
F : Type uF
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
s : Set E
f : E → F
x : E
n : ℕ∞ω
hn : n ≠ ∞
h'n : n + 1 ≠ ∞
u : Set E
hu : u ∈ 𝓝[insert x s] x
hf : n = ω → AnalyticOn 𝕜 f u
f' : E → E →L[𝕜] F
f'_eq_deriv : ∀ x ∈ u, HasFDerivWithinAt f (f' x) u x
Hf' : ContDiffWithinAt 𝕜 n f' u x
v : Set E
hv : v ∈ 𝓝[insert x u] x
p' : E → FormalMultilinearSeries 𝕜 E (E →L[𝕜] F)
Hp' : HasFTaylorSeriesUpToOn n f' p' v
p'_an : n = ω → ∀ (i : ℕ), AnalyticOn 𝕜 (fun x ↦ p' x i) v
y : E
hy : y ∈ v ∩ u
⊢ ↑↑(continuousMultilinearCurryFin0 𝕜 E F).symm.symm ∘SL ((p' y).unshift (f y) 1).curryLeft = f' y
Module: Mathlib.Analysis.Calculus.ContDiff.FaaDiBruno

Goal state before:
pp: case inr
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
F : Type u_3
inst✝³ : NormedAddCommGroup F
inst✝² : NormedSpace 𝕜 F
G : Type u_4
inst✝¹ : NormedAddCommGroup G
inst✝ : NormedSpace 𝕜 G
s : Set E
t : Set F
q : F → FormalMultilinearSeries 𝕜 F G
p : E → FormalMultilinearSeries 𝕜 E F
n : ℕ
c✝ : OrderedFinpartition n
c : OrderedFinpartition (n + 1)
hc : range (c.emb 0) ≠ {0}
i : Fin c.length
hi : i ≠ c.index 0
⊢ 0 < update c.partSize (c.index 0) (c.partSize (c.index 0) - 1) i

Tactic:
simp only [ne_eq, hi, not_false_eq_true, update_of_ne]
      exact c.partSize_pos i

Goal state after:
Module: Mathlib.Analysis.Calculus.ContDiff.Defs

Goal state before:
pp: 𝕜 : Type u
inst✝⁴ : NontriviallyNormedField 𝕜
E : Type uE
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
F : Type uF
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
f : E → F
x : E
⊢ ContDiffAt 𝕜 ∞ f x ↔ ∀ (n : ℕ), ContDiffAt 𝕜 (↑n) f x

Tactic:
simp [← contDiffWithinAt_univ, contDiffWithinAt_infty]

Goal state after:
Module: Mathlib.Analysis.Calculus.ContDiff.Defs

Goal state before:
pp: 𝕜 : Type u
inst✝⁴ : NontriviallyNormedField 𝕜
E : Type uE
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
F : Type uF
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
f : E → F
x : E
n : ℕ
⊢ ContDiffAt 𝕜 (↑n + 1) f x ↔ ∃ f', (∃ u ∈ 𝓝 x, ∀ x ∈ u, HasFDerivAt f (f' x) x) ∧ ContDiffAt 𝕜 (↑n) f' x

Tactic:
rw [← contDiffWithinAt_univ, contDiffWithinAt_succ_iff_hasFDerivWithinAt (by simp)]

Goal state after:
𝕜 : Type u
inst✝⁴ : NontriviallyNormedField 𝕜
E : Type uE
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
F : Type uF
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
f : E → F
x : E
n : ℕ
⊢ (∃ u ∈ 𝓝[insert x univ] x,
      (↑n = ω → AnalyticOn 𝕜 f u) ∧ ∃ f', (∀ x ∈ u, HasFDerivWithinAt f (f' x) u x) ∧ ContDiffWithinAt 𝕜 (↑n) f' u x) ↔
    ∃ f', (∃ u ∈ 𝓝 x, ∀ x ∈ u, HasFDerivAt f (f' x) x) ∧ ContDiffAt 𝕜 (↑n) f' x
Module: Mathlib.Analysis.Normed.Algebra.Exponential

Goal state before:
pp: ι : Type u_3
𝔸 : ι → Type u_4
inst✝⁴ : Finite ι
inst✝³ : DecidableEq ι
inst✝² : (i : ι) → NormedRing (𝔸 i)
inst✝¹ : (i : ι) → NormedAlgebra ℚ (𝔸 i)
inst✝ : ∀ (i : ι), CompleteSpace (𝔸 i)
x : (i : ι) → 𝔸 i
j : ι
xj : 𝔸 j
i : ι
⊢ Function.update (exp x) j (exp xj) i = exp (Function.update x j xj) i

Tactic:
Pi.exp_def

Goal state after:
ι : Type u_3
𝔸 : ι → Type u_4
inst✝⁴ : Finite ι
inst✝³ : DecidableEq ι
inst✝² : (i : ι) → NormedRing (𝔸 i)
inst✝¹ : (i : ι) → NormedAlgebra ℚ (𝔸 i)
inst✝ : ∀ (i : ι), CompleteSpace (𝔸 i)
x : (i : ι) → 𝔸 i
j : ι
xj : 𝔸 j
i : ι
⊢ Function.update (fun i ↦ exp (x i)) j (exp xj) i = exp (Function.update x j xj i)
Module: Mathlib.Analysis.Calculus.ContDiff.FaaDiBruno

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
F : Type u_3
inst✝³ : NormedAddCommGroup F
inst✝² : NormedSpace 𝕜 F
G : Type u_4
inst✝¹ : NormedAddCommGroup G
inst✝ : NormedSpace 𝕜 G
m : ℕ
q : FormalMultilinearSeries 𝕜 F G
p : FormalMultilinearSeries 𝕜 E F
c : OrderedFinpartition m
i : Fin c.length
e : E
v : Fin m → E
⊢ ((q.compAlongOrderedFinpartition p (c.extend (some i))).curryLeft e) v =
    ((((compAlongOrderedFinpartitionL 𝕜 E F G c) (q c.length)).toContinuousLinearMap (fun i ↦ p (c.partSize i)) i ∘SL
          (p (c.partSize i + 1)).curryLeft)
        e)
      v

Tactic:
simp? [OrderedFinpartition.extend, extendMiddle, applyOrderedFinpartition_apply] says
    simp only [OrderedFinpartition.extend, extendMiddle, ContinuousMultilinearMap.curryLeft_apply,
      Nat.succ_eq_add_one, FormalMultilinearSeries.compAlongOrderedFinpartition_apply,
      applyOrderedFinpartition_apply, ContinuousLinearMap.comp_apply,
      ContinuousMultilinearMap.toContinuousLinearMap_apply, compAlongOrderedFinpartitionL_apply,
      compAlongOrderFinpartition_apply]

Goal state after:
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
F : Type u_3
inst✝³ : NormedAddCommGroup F
inst✝² : NormedSpace 𝕜 F
G : Type u_4
inst✝¹ : NormedAddCommGroup G
inst✝ : NormedSpace 𝕜 G
m : ℕ
q : FormalMultilinearSeries 𝕜 F G
p : FormalMultilinearSeries 𝕜 E F
c : OrderedFinpartition m
i : Fin c.length
e : E
v : Fin m → E
⊢ ((q c.length) fun m_1 ↦
      (p (update c.partSize i (c.partSize i + 1) m_1))
        (cons e v ∘
          if h : m_1 = i then (fun i_1 ↦ cases 0 (succ ∘ c.emb i) i_1) ∘ Fin.cast ⋯
          else succ ∘ c.emb m_1 ∘ Fin.cast ⋯)) =
    (q c.length) fun m_1 ↦
      (update (fun i ↦ p (c.partSize i)) i ((p (c.partSize i + 1)).curryLeft e) m_1) (v ∘ c.emb m_1)
Module: Mathlib.Analysis.Calculus.ContDiff.Operations

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁵ : NontriviallyNormedField 𝕜
E : Type uE
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
F : Type uF
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
n : ℕ∞ω
inst✝ : CompleteSpace E
f : OpenPartialHomeomorph E F
f₀' : E ≃L[𝕜] F
a : F
ha : a ∈ f.target
hf₀' : HasFDerivAt (↑f) (↑f₀') (↑f.symm a)
hf : ContDiffAt 𝕜 ω (↑f) (↑f.symm a)
⊢ AnalyticAt 𝕜 (↑f.symm) a

Tactic:
exact f.analyticAt_symm ha hf.analyticAt hf₀'.fderiv

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Bochner.VitaliCaratheodory

Goal state before:
pp: α : Type u_1
inst✝³ : TopologicalSpace α
inst✝² : MeasurableSpace α
inst✝¹ : BorelSpace α
μ : Measure α
inst✝ : μ.WeaklyRegular
f : α → ℝ≥0∞
hf : Measurable f
ε : ℝ≥0∞
εpos : ε ≠ 0
δ : ℕ → ℝ≥0∞
δpos : ∀ (i : ℕ), 0 < δ i
hδ : ∑' (i : ℕ), δ i < ε
this :
  ∀ (n : ℕ),
    ∃ g,
      (∀ (x : α), (eapproxDiff f n) x ≤ g x) ∧
        LowerSemicontinuous g ∧ ∫⁻ (x : α), ↑(g x) ∂μ ≤ ∫⁻ (x : α), ↑((eapproxDiff f n) x) ∂μ + δ n
⊢ ∃ g, (∀ (x : α), f x ≤ g x) ∧ LowerSemicontinuous g ∧ ∫⁻ (x : α), g x ∂μ ≤ ∫⁻ (x : α), f x ∂μ + ε

Tactic:
choose g f_le_g gcont hg using this

Goal state after:
α : Type u_1
inst✝³ : TopologicalSpace α
inst✝² : MeasurableSpace α
inst✝¹ : BorelSpace α
μ : Measure α
inst✝ : μ.WeaklyRegular
f : α → ℝ≥0∞
hf : Measurable f
ε : ℝ≥0∞
εpos : ε ≠ 0
δ : ℕ → ℝ≥0∞
δpos : ∀ (i : ℕ), 0 < δ i
hδ : ∑' (i : ℕ), δ i < ε
g : ℕ → α → ℝ≥0
f_le_g : ∀ (n : ℕ) (x : α), (eapproxDiff f n) x ≤ g n x
gcont : ∀ (n : ℕ), LowerSemicontinuous (g n)
hg : ∀ (n : ℕ), ∫⁻ (x : α), ↑(g n x) ∂μ ≤ ∫⁻ (x : α), ↑((eapproxDiff f n) x) ∂μ + δ n
⊢ ∃ g, (∀ (x : α), f x ≤ g x) ∧ LowerSemicontinuous g ∧ ∫⁻ (x : α), g x ∂μ ≤ ∫⁻ (x : α), f x ∂μ + ε
Module: Mathlib.Analysis.SpecialFunctions.Log.Deriv

Goal state before:

Tactic:
-y ^ n / (1 - y) = ∑ i ∈ Finset.range n, y ^ i + -1 / (1 - y) := by
        simp [field, geom_sum_eq hy.2.ne, sub_ne_zero.2 hy.2.ne, sub_ne_zero.2 hy.2.ne']
        ring
      _ = ∑ i ∈ Finset.range n, ↑(i + 1) * y ^ i / (↑i + 1) + -1 / (1 - y) := by
        congr with i
        rw [Nat.cast_succ, mul_div_cancel_left₀ _ (Nat.cast_add_one_pos i).ne']

Goal state after:
Module: Mathlib.Geometry.Convex.Cone.Pointed

Goal state before:
pp: R : Type u_1
E : Type u_2
inst✝⁴ : Semiring R
inst✝³ : PartialOrder R
inst✝² : IsOrderedRing R
inst✝¹ : AddCommMonoid E
inst✝ : Module R E
s : Set (Submodule R E)
⊢ ⨆ a ∈ ofSubmodule '' s, a = ⨆ S ∈ s, ↑S

Tactic:
iSup_image

Goal state after:
R : Type u_1
E : Type u_2
inst✝⁴ : Semiring R
inst✝³ : PartialOrder R
inst✝² : IsOrderedRing R
inst✝¹ : AddCommMonoid E
inst✝ : Module R E
s : Set (Submodule R E)
⊢ ⨆ b ∈ s, ↑b = ⨆ S ∈ s, ↑S
Module: Mathlib.MeasureTheory.Integral.Bochner.VitaliCaratheodory

Goal state before:
pp: case neg.refine_2
α : Type u_1
inst✝³ : TopologicalSpace α
inst✝² : MeasurableSpace α
inst✝¹ : BorelSpace α
μ : Measure α
inst✝ : μ.WeaklyRegular
c : ℝ≥0
s : Set α
hs : MeasurableSet s
int_f : ∫⁻ (x : α), ↑((piecewise s hs (const α c) (const α 0)) x) ∂μ ≠ ∞
ε : ℝ≥0∞
ε0 : ε ≠ 0
hc : ¬c = 0
μs_lt_top : μ s < ∞
this : 0 < ε / ↑c
F : Set α
Fs : F ⊆ s
F_closed : IsClosed F
μF : μ s < μ F + ε / ↑c
⊢ ∫⁻ (x : α), ↑((piecewise s hs (const α c) (const α 0)) x) ∂μ ≤ ∫⁻ (x : α), ↑(F.indicator (fun x ↦ c) x) ∂μ + ε

Tactic:
suffices (c : ℝ≥0∞) * μ s ≤ c * μ F + ε by
        simpa only [hs, F_closed.measurableSet, SimpleFunc.coe_const, Function.const_apply,
          lintegral_const, ENNReal.coe_indicator, Set.univ_inter, MeasurableSet.univ,
          SimpleFunc.const_zero, lintegral_indicator, SimpleFunc.coe_zero,
          Set.piecewise_eq_indicator, SimpleFunc.coe_piecewise, Measure.restrict_apply]
      calc
        (c : ℝ≥0∞) * μ s ≤ c * (μ F + ε / c) := by grw [μF]
        _ = c * μ F + ε := by
          simp_rw [mul_add]
          rw [ENNReal.mul_div_cancel _ ENNReal.coe_ne_top]
          simpa using hc

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Log.Deriv

Goal state before:
pp: a : ℝ
h : 0 < a
⊢ 0 < 1 / (2 * a + 1)

Tactic:
exact div_pos one_pos (by linarith)

Goal state after:
Module: Mathlib.Analysis.Convex.Gauge

Goal state before:
pp: E : Type u_2
inst✝³ : AddCommGroup E
inst✝² : Module ℝ E
s : Set E
inst✝¹ : TopologicalSpace E
inst✝ : ContinuousSMul ℝ E
hs : s ∈ 𝓝 0
⊢ Tendsto (gauge s) (𝓝 0) (𝓝[≥] 0)

Tactic:
by
  refine nhdsGE_basis_Icc.tendsto_right_iff.2 fun ε hε ↦ ?_
  rw [← set_smul_mem_nhds_zero_iff hε.ne'] at hs
  filter_upwards [hs] with x hx
  exact ⟨gauge_nonneg _, gauge_le_of_mem hε.le hx⟩

Goal state after:
Module: Mathlib.Analysis.LocallyConvex.SeparatingDual

Goal state before:
pp: R : Type u_1
V : Type u_2
inst✝⁶ : Field R
inst✝⁵ : AddCommGroup V
inst✝⁴ : TopologicalSpace R
inst✝³ : TopologicalSpace V
inst✝² : IsTopologicalRing R
inst✝¹ : Module R V
inst✝ : SeparatingDual R V
x y : V
hx : x ≠ 0
hy : y ≠ 0
⊢ ∃ f, f x = 1 ∧ f y ≠ 0

Tactic:
obtain ⟨u, ux⟩ : ∃ u : StrongDual R V, u x = 1 := exists_eq_one hx
  rcases ne_or_eq (u y) 0 with uy | uy
  · exact ⟨u, ux, uy⟩
  obtain ⟨v, vy⟩ : ∃ v : StrongDual R V, v y = 1 := exists_eq_one hy
  rcases ne_or_eq (v x) 0 with vx | vx
  · exact ⟨(v x)⁻¹ • v, inv_mul_cancel₀ vx, show (v x)⁻¹ * v y ≠ 0 by simp [vx, vy]⟩
  · exact ⟨u + v, by simp [ux, vx], by simp [uy, vy]⟩

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

Goal state before:
pp: F : Type u_1
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
f : ℝ → F
ε : ℝ
hε : 0 < ε
x : ℝ
hx : DifferentiableWithinAt ℝ f (Ici x) x
⊢ ∃ R > 0, ∀ r ∈ Ioo 0 R, x ∈ A f (derivWithin f (Ici x) x) r ε

Tactic:
have := hx.hasDerivWithinAt
  simp_rw [hasDerivWithinAt_iff_isLittleO, isLittleO_iff] at this
  rcases mem_nhdsGE_iff_exists_Ico_subset.1 (this (half_pos hε)) with ⟨m, xm, hm⟩
  refine ⟨m - x, by linarith [show x < m from xm], fun r hr => ?_⟩
  have : r ∈ Ioc (r / 2) r := ⟨half_lt_self hr.1, le_rfl⟩
  refine ⟨r, this, fun y hy z hz => ?_⟩
  calc
    ‖f z - f y - (z - y) • derivWithin f (Ici x) x‖ =
        ‖f z - f x - (z - x) • derivWithin f (Ici x) x -
            (f y - f x - (y - x) • derivWithin f (Ici x) x)‖ := by
      congr 1; simp only [sub_smul]; abel
    _ ≤
        ‖f z - f x - (z - x) • derivWithin f (Ici x) x‖ +
          ‖f y - f x - (y - x) • derivWithin f (Ici x) x‖ :=
      (norm_sub_le _ _)
    _ ≤ ε / 2 * ‖z - x‖ + ε / 2 * ‖y - x‖ :=
      (add_le_add (hm ⟨hz.1, hz.2.trans_lt (by linarith [hr.2])⟩)
        (hm ⟨hy.1, hy.2.trans_lt (by linarith [hr.2])⟩))
    _ ≤ ε / 2 * r + ε / 2 * r := by
      gcongr
      · rw [Real.norm_of_nonneg] <;> linarith [hz.1, hz.2]
      · rw [Real.norm_of_nonneg] <;> linarith [hy.1, hy.2]
    _ = ε * r := by ring

Goal state after:
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.Basic

Goal state before:
pp: ι : Type u_1
a b : ℝ
μ : Measure ℝ
ε : Type u_8
inst✝³ : TopologicalSpace ε
inst✝² : ENormedAddCommMonoid ε
inst✝¹ : ContinuousAdd ε
inst✝ : PseudoMetrizableSpace ε
f : ι → ℝ → ε
h : ∀ (i : ι), IntervalIntegrable (f i) μ a b
⊢ IntervalIntegrable (∑ᶠ (i : ι), f i) μ a b

Tactic:
by
  by_cases h₁ : f.support.Finite
  · simp [finsum_eq_sum _ h₁, IntervalIntegrable.sum h₁.toFinset (fun i _ ↦ h i)]
  · rw [finsum_of_infinite_support h₁]
    apply intervalIntegrable_const_iff (c := 0) (by simp) |>.2
    tauto

Goal state after:
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.FundThmCalculus

Goal state before:
pp: g' g φ : ℝ → ℝ
a b : ℝ
hab : a ≤ b
hcont : ContinuousOn g (Icc a b)
hderiv : ∀ x ∈ Ico a b, HasDerivWithinAt g (g' x) (Ioi x) x
φint : IntegrableOn φ (Icc a b) volume
hφg : ∀ x ∈ Ico a b, g' x ≤ φ x
ε : ℝ
εpos : 0 < ε
G' : ℝ → EReal
f_lt_G' : ∀ (x : ℝ), ↑(φ x) < G' x
G'cont : LowerSemicontinuous G'
G'int : Integrable (fun x ↦ (G' x).toReal) (volume.restrict (Icc a b))
G'lt_top : ∀ᵐ (x : ℝ) ∂volume.restrict (Icc a b), G' x < ⊤
hG' : ∫ (x : ℝ) in Icc a b, (G' x).toReal < (∫ (x : ℝ) in Icc a b, φ x) + ε
s : Set ℝ := {t | g t - g a ≤ ∫ (u : ℝ) in a..t, (G' u).toReal} ∩ Icc a b
⊢ g b - g a ≤ (∫ (y : ℝ) in a..b, φ y) + ε

Tactic:
have s_closed : IsClosed s := by
    have : ContinuousOn (fun t => (g t - g a, ∫ u in a..t, (G' u).toReal)) (Icc a b) := by
      rw [← uIcc_of_le hab] at G'int hcont ⊢
      exact (hcont.sub continuousOn_const).prodMk (continuousOn_primitive_interval G'int)
    simp only [s, inter_comm]
    exact this.preimage_isClosed_of_isClosed isClosed_Icc OrderClosedTopology.isClosed_le'

Goal state after:
g' g φ : ℝ → ℝ
a b : ℝ
hab : a ≤ b
hcont : ContinuousOn g (Icc a b)
hderiv : ∀ x ∈ Ico a b, HasDerivWithinAt g (g' x) (Ioi x) x
φint : IntegrableOn φ (Icc a b) volume
hφg : ∀ x ∈ Ico a b, g' x ≤ φ x
ε : ℝ
εpos : 0 < ε
G' : ℝ → EReal
f_lt_G' : ∀ (x : ℝ), ↑(φ x) < G' x
G'cont : LowerSemicontinuous G'
G'int : Integrable (fun x ↦ (G' x).toReal) (volume.restrict (Icc a b))
G'lt_top : ∀ᵐ (x : ℝ) ∂volume.restrict (Icc a b), G' x < ⊤
hG' : ∫ (x : ℝ) in Icc a b, (G' x).toReal < (∫ (x : ℝ) in Icc a b, φ x) + ε
s : Set ℝ := {t | g t - g a ≤ ∫ (u : ℝ) in a..t, (G' u).toReal} ∩ Icc a b
s_closed : IsClosed s
⊢ g b - g a ≤ (∫ (y : ℝ) in a..b, φ y) + ε
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.Basic

Goal state before:
pp: E : Type u_5
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
a b c : ℝ
f : ℝ → E
hc : c ≠ 0
⊢ ∫ (x : ℝ) in a..b, f (x * c) = c⁻¹ • ∫ (x : ℝ) in a * c..b * c, f x

Tactic:
by
  have A : MeasurableEmbedding fun x => x * c :=
    (Homeomorph.mulRight₀ c hc).isClosedEmbedding.measurableEmbedding
  conv_rhs => rw [← Real.smul_map_volume_mul_right hc]
  simp_rw [integral_smul_measure, intervalIntegral, A.setIntegral_map,
    ENNReal.toReal_ofReal (abs_nonneg c)]
  rcases hc.lt_or_gt with h | h
  · simp [h, mul_div_cancel_right₀, hc, abs_of_neg,
      Measure.restrict_congr_set (α := ℝ) (μ := volume) Ico_ae_eq_Ioc]
  · simp [h, mul_div_cancel_right₀, hc, abs_of_pos]

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.NonIntegrable

Goal state before:
pp: E : Type u_1
F : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : NormedAddCommGroup F
inst✝² : CompleteSpace E
f : ℝ → E
g : ℝ → F
k : Set ℝ
l : Filter ℝ
inst✝¹ : l.NeBot
inst✝ : TendstoIxxClass Icc l l
hl : k ∈ l
hd✝ : ∀ᶠ (x : ℝ) in l, DifferentiableAt ℝ f x
hf : Tendsto (fun x ↦ ‖f x‖) l atTop
hfg : deriv f =O[l] g
C : ℝ
hC₀ : 0 ≤ C
s : Set ℝ
hsl : s ∈ l
hgi : IntegrableOn (fun x ↦ C * ‖g x‖) k volume
c : ℝ
hc : c ∈ s
d : ℝ
hfd : ∀ z ∈ [[c, d]], DifferentiableAt ℝ f z
hsub : [[c, d]] ⊆ k
hd : d ∈ s
hlt : ‖f c‖ + ∫ (y : ℝ) in k, C * ‖g y‖ < ‖f d‖
hg : ∀ x ∈ Ι c d, ‖deriv f x‖ ≤ C * ‖g x‖
hg_ae : ∀ᵐ (x : ℝ) ∂volume.restrict (Ι c d), ‖deriv f x‖ ≤ C * ‖g x‖
hsub' : Ι c d ⊆ k
⊢ IntegrableOn (deriv f) (Ι c d) volume

Tactic:
have : IntegrableOn (fun x ↦ C * ‖g x‖) (Ι c d) := IntegrableOn.mono hgi hsub' le_rfl

Goal state after:
E : Type u_1
F : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : NormedAddCommGroup F
inst✝² : CompleteSpace E
f : ℝ → E
g : ℝ → F
k : Set ℝ
l : Filter ℝ
inst✝¹ : l.NeBot
inst✝ : TendstoIxxClass Icc l l
hl : k ∈ l
hd✝ : ∀ᶠ (x : ℝ) in l, DifferentiableAt ℝ f x
hf : Tendsto (fun x ↦ ‖f x‖) l atTop
hfg : deriv f =O[l] g
C : ℝ
hC₀ : 0 ≤ C
s : Set ℝ
hsl : s ∈ l
hgi : IntegrableOn (fun x ↦ C * ‖g x‖) k volume
c : ℝ
hc : c ∈ s
d : ℝ
hfd : ∀ z ∈ [[c, d]], DifferentiableAt ℝ f z
hsub : [[c, d]] ⊆ k
hd : d ∈ s
hlt : ‖f c‖ + ∫ (y : ℝ) in k, C * ‖g y‖ < ‖f d‖
hg : ∀ x ∈ Ι c d, ‖deriv f x‖ ≤ C * ‖g x‖
hg_ae : ∀ᵐ (x : ℝ) ∂volume.restrict (Ι c d), ‖deriv f x‖ ≤ C * ‖g x‖
hsub' : Ι c d ⊆ k
this : IntegrableOn (fun x ↦ C * ‖g x‖) (Ι c d) volume
⊢ IntegrableOn (deriv f) (Ι c d) volume
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.Basic

Goal state before:
pp: E : Type u_5
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
a b : ℝ
f : ℝ → E
μ : Measure ℝ
hf : IntegrableOn f (Iio b) μ
hab : a ≤ b
ha : IntegrableOn f (Iio a) μ
h : IntegrableOn f (Ico a b) μ
⊢ ∫ (x : ℝ) in Iio b, f x ∂μ = ∫ (x : ℝ) in Iio a ∪ Ico a b, f x ∂μ

Tactic:
Iio_union_Ico_eq_Iio hab

Goal state after:
E : Type u_5
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
a b : ℝ
f : ℝ → E
μ : Measure ℝ
hf : IntegrableOn f (Iio b) μ
hab : a ≤ b
ha : IntegrableOn f (Iio a) μ
h : IntegrableOn f (Ico a b) μ
⊢ ∫ (x : ℝ) in Iio b, f x ∂μ = ∫ (x : ℝ) in Iio b, f x ∂μ
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.Basic

Goal state before:
pp: f : ℝ → ℝ
a b : ℝ
μ : Measure ℝ
hf : 0 ≤ᵐ[μ.restrict (Ioc a b ∪ Ioc b a)] f
hfi : IntervalIntegrable f μ a b
⊢ ∫ (x : ℝ) in a..b, f x ∂μ = 0 ↔ f =ᵐ[μ.restrict (Ioc a b ∪ Ioc b a)] 0

Tactic:
rcases le_total a b with hab | hab <;>
    simp only [Ioc_eq_empty hab.not_gt, empty_union, union_empty] at hf ⊢

Goal state after:
case inl
f : ℝ → ℝ
a b : ℝ
μ : Measure ℝ
hfi : IntervalIntegrable f μ a b
hab : a ≤ b
hf : 0 ≤ᵐ[μ.restrict (Ioc a b)] f
⊢ ∫ (x : ℝ) in a..b, f x ∂μ = 0 ↔ f =ᵐ[μ.restrict (Ioc a b)] 0

case inr
f : ℝ → ℝ
a b : ℝ
μ : Measure ℝ
hfi : IntervalIntegrable f μ a b
hab : b ≤ a
hf : 0 ≤ᵐ[μ.restrict (Ioc b a)] f
⊢ ∫ (x : ℝ) in a..b, f x ∂μ = 0 ↔ f =ᵐ[μ.restrict (Ioc b a)] 0
Module: Mathlib.MeasureTheory.Measure.Haar.Quotient

Goal state before:
pp: G : Type u_1
inst✝¹² : Group G
inst✝¹¹ : MeasurableSpace G
inst✝¹⁰ : TopologicalSpace G
inst✝⁹ : IsTopologicalGroup G
inst✝⁸ : BorelSpace G
inst✝⁷ : PolishSpace G
Γ : Subgroup G
inst✝⁶ : Γ.Normal
inst✝⁵ : T2Space (G ⧸ Γ)
inst✝⁴ : SecondCountableTopology (G ⧸ Γ)
inst✝³ : Countable ↥Γ
ν : Measure G
inst✝² : ν.IsHaarMeasure
inst✝¹ : ν.IsMulRightInvariant
inst✝ : SigmaFinite ν
K : PositiveCompacts (G ⧸ Γ)
𝓕 : Set G
h𝓕 : IsFundamentalDomain (↥Γ.op) 𝓕 ν
h𝓕_finite : ν 𝓕 ≠ ∞
⊢ QuotientMeasureEqMeasurePreimage ν (ν (QuotientGroup.mk ⁻¹' ↑K ∩ 𝓕) • haarMeasure K)

Tactic:
by
  set c := ν ((π ⁻¹' (K : Set (G ⧸ Γ))) ∩ 𝓕)
  have c_ne_top : c ≠ ∞ := measure_inter_ne_top_of_right_ne_top h𝓕_finite
  set μ := c • haarMeasure K
  have hμK : μ K = c := by simp [μ, haarMeasure_self]
  have : SigmaFinite μ := by
    clear_value c
    lift c to NNReal using c_ne_top
    exact SMul.sigmaFinite c
  apply IsFundamentalDomain.QuotientMeasureEqMeasurePreimage_HaarMeasure (h𝓕 := h𝓕)
    (meas_V := K.isCompact.measurableSet) (μ := μ)
  · exact K.interior_nonempty
  · exact hμK
  · rw [hμK]
    exact c_ne_top

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

Goal state before:
pp: case h
E : Type u_1
X : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
inst✝² : TopologicalSpace X
μ : Measure ℝ
inst✝¹ : NullSingletonClass μ
inst✝ : IsLocallyFiniteMeasure μ
f : X → ℝ → E
a₀ : ℝ
hf : Continuous[instTopologicalSpaceProd, PseudoMetricSpace.toUniformSpace.toTopologicalSpace] (Function.uncurry f)
q : X
b₀ ε : ℝ
εpos : ε > 0
a : ℝ
a_lt : a < a₀ ∧ a < b₀
b : ℝ
lt_b : a₀ < b ∧ b₀ < b
this✝ : IsCompact ({q} ×ˢ Icc a b)
M : ℝ
hM : M ∈ upperBounds ((fun x ↦ ‖Function.uncurry f x‖) '' {q} ×ˢ Icc a b)
δ : ℝ
δpos : 0 < δ
hδ : δ < 1
h'δ : Icc (b₀ - δ) (b₀ + δ) ⊆ Icc a b
h''δ : (M + 1) * μ.real (Icc (b₀ - δ) (b₀ + δ)) + δ * μ.real (Icc a b) < ε
v : Set X
v_mem : v ∈ 𝓝[univ] q
this : v ×ˢ Ioo (b₀ - δ) (b₀ + δ) ∈ 𝓝 (q, b₀)
p : X
s : ℝ
hp : p ∈ v
hs : s ∈ Ioo (b₀ - δ) (b₀ + δ)
hv : ∀ p ∈ v, ∀ x ∈ Icc a b, ‖f p x - f q x‖ < δ
J : ∀ (r : X) (u v : ℝ), IntervalIntegrable (f r) μ u v
x : ℝ
hx : x ∈ Icc (b₀ - δ) (b₀ + δ)
⊢ ‖f p x‖ ≤ M + 1

Tactic:
calc ‖f p x‖ = ‖f q x + (f p x - f q x)‖ := by congr; abel
        _ ≤ ‖f q x‖ + ‖f p x - f q x‖ := norm_add_le _ _
        _ ≤ M + δ := by
            gcongr
            · apply hM
              change (fun x ↦ ‖Function.uncurry f x‖) (q, x) ∈ _
              apply mem_image_of_mem
              simp only [singleton_prod, mem_image, Prod.mk.injEq, true_and, exists_eq_right]
              exact h'δ hx
            · exact le_of_lt (hv _ hp _ (h'δ hx))
        _ ≤ M + 1 := by linarith

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

Goal state before:
pp: E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
μ : Measure ℝ
f : ℝ → E
inst✝ : NullSingletonClass μ
a₀ : ℝ
hf : IntegrableOn f (Ioi a₀) μ
a : ℝ
⊢ a ∈ Ici a₀ → ContinuousWithinAt (fun b ↦ ∫ (x : ℝ) in Ioi b, f x ∂μ) (Ici a₀) a

Tactic:
(ha : a₀ ≤ a)

Goal state after:
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
μ : Measure ℝ
f : ℝ → E
inst✝ : NullSingletonClass μ
a₀ : ℝ
hf : IntegrableOn f (Ioi a₀) μ
a : ℝ
ha : a₀ ≤ a
⊢ ContinuousWithinAt (fun b ↦ ∫ (x : ℝ) in Ioi b, f x ∂μ) (Ici a₀) a