mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Calculus.ContDiff.Bounds

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type uE
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
Fu : Type u
inst✝³ : NormedAddCommGroup Fu
inst✝² : NormedSpace 𝕜 Fu
f : E → Fu
s : Set E
t : Set Fu
x : E
ht : UniqueDiffOn 𝕜 t
hs : UniqueDiffOn 𝕜 s
hst : MapsTo f s t
hx : x ∈ s
C D : ℝ
n : ℕ
IH :
  ∀ m ≤ n,
    ∀ {Gu : Type u} [inst : NormedAddCommGroup Gu] [inst_1 : NormedSpace 𝕜 Gu] {g : Fu → Gu},
      ContDiffOn 𝕜 (↑m) g t →
        ContDiffOn 𝕜 (↑m) f s →
          (∀ i ≤ m, ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ ≤ C) →
            (∀ (i : ℕ), 1 ≤ i → i ≤ m → ‖iteratedFDerivWithin 𝕜 i f s x‖ ≤ D ^ i) →
              ‖iteratedFDerivWithin 𝕜 m (g ∘ f) s x‖ ≤ ↑m ! * C * D ^ m
Gu : Type u
inst✝¹ : NormedAddCommGroup Gu
inst✝ : NormedSpace 𝕜 Gu
g : Fu → Gu
hg : ContDiffOn 𝕜 (↑(n + 1)) g t
hf : ContDiffOn 𝕜 (↑(n + 1)) f s
hC : ∀ i ≤ n + 1, ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ ≤ C
hD : ∀ (i : ℕ), 1 ≤ i → i ≤ n + 1 → ‖iteratedFDerivWithin 𝕜 i f s x‖ ≤ D ^ i
M : ↑n < ↑n.succ
Cnonneg : 0 ≤ C
Dnonneg : 0 ≤ D
I : ∀ i ∈ Finset.range (n + 1), ‖iteratedFDerivWithin 𝕜 i (fderivWithin 𝕜 g t ∘ f) s x‖ ≤ ↑i ! * C * D ^ i
J : ∀ (i : ℕ), ‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 f s) s x‖ ≤ D ^ (n - i + 1)
⊢ iteratedFDerivWithin 𝕜 n (fun y ↦ fderivWithin 𝕜 (g ∘ f) s y) s x =
    iteratedFDerivWithin 𝕜 n
      (fun y ↦ ((ContinuousLinearMap.compL 𝕜 E Fu Gu) (fderivWithin 𝕜 g t (f y))) (fderivWithin 𝕜 f s y)) s x

Tactic:
refine iteratedFDerivWithin_congr (fun y hy => ?_) hx _

Goal state after:
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type uE
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
Fu : Type u
inst✝³ : NormedAddCommGroup Fu
inst✝² : NormedSpace 𝕜 Fu
f : E → Fu
s : Set E
t : Set Fu
x : E
ht : UniqueDiffOn 𝕜 t
hs : UniqueDiffOn 𝕜 s
hst : MapsTo f s t
hx : x ∈ s
C D : ℝ
n : ℕ
IH :
  ∀ m ≤ n,
    ∀ {Gu : Type u} [inst : NormedAddCommGroup Gu] [inst_1 : NormedSpace 𝕜 Gu] {g : Fu → Gu},
      ContDiffOn 𝕜 (↑m) g t →
        ContDiffOn 𝕜 (↑m) f s →
          (∀ i ≤ m, ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ ≤ C) →
            (∀ (i : ℕ), 1 ≤ i → i ≤ m → ‖iteratedFDerivWithin 𝕜 i f s x‖ ≤ D ^ i) →
              ‖iteratedFDerivWithin 𝕜 m (g ∘ f) s x‖ ≤ ↑m ! * C * D ^ m
Gu : Type u
inst✝¹ : NormedAddCommGroup Gu
inst✝ : NormedSpace 𝕜 Gu
g : Fu → Gu
hg : ContDiffOn 𝕜 (↑(n + 1)) g t
hf : ContDiffOn 𝕜 (↑(n + 1)) f s
hC : ∀ i ≤ n + 1, ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ ≤ C
hD : ∀ (i : ℕ), 1 ≤ i → i ≤ n + 1 → ‖iteratedFDerivWithin 𝕜 i f s x‖ ≤ D ^ i
M : ↑n < ↑n.succ
Cnonneg : 0 ≤ C
Dnonneg : 0 ≤ D
I : ∀ i ∈ Finset.range (n + 1), ‖iteratedFDerivWithin 𝕜 i (fderivWithin 𝕜 g t ∘ f) s x‖ ≤ ↑i ! * C * D ^ i
J : ∀ (i : ℕ), ‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 f s) s x‖ ≤ D ^ (n - i + 1)
y : E
hy : y ∈ s
⊢ fderivWithin 𝕜 (g ∘ f) s y = ((ContinuousLinearMap.compL 𝕜 E Fu Gu) (fderivWithin 𝕜 g t (f y))) (fderivWithin 𝕜 f s y)
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
⊢ μ (⋃ x, closedBall (↑x) (r0 ↑x)) ≤ μ u

Tactic:
apply measure_mono

Goal state after:
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'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 := ⋯
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 := ⋯
r_t0 : ∀ x ∈ t0, r x = r0 x
⊢ ⋃ x, closedBall (↑x) (r0 ↑x) ⊆ u
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
i : Fin N
⊢ μ (⋃ x, closedBall (↑↑x) (r1 ↑↑x)) ≤ μ v

Tactic:
apply measure_mono

Goal state after:
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'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 := ⋯
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 := ⋯
r_t0 : ∀ x ∈ t0, r x = r0 x
A : ∑' (x : ↑t0), μ (closedBall (↑x) (r ↑x)) ≤ μ s + ε / 2
i : Fin N
⊢ ⋃ x, closedBall (↑↑x) (r1 ↑↑x) ⊆ v
Module: Mathlib.Analysis.Calculus.FDeriv.Symmetric

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁵ : NontriviallyNormedField 𝕜
E : Type u_2
F : Type u_3
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
f : E → F
inst✝ : IsRCLikeNormedField 𝕜
f' : E → E →L[𝕜] F
x : E
f'' : E →L[𝕜] E →L[𝕜] F
hf : ∀ᶠ (y : E) in 𝓝 x, HasFDerivAt f (f' y) y
hx : HasFDerivAt f' f'' x
v w : E
⊢ (f'' v) w = (f'' w) v

Tactic:
by
  let _ := IsRCLikeNormedField.rclike 𝕜
  let _ : NormedSpace ℝ E := NormedSpace.restrictScalars ℝ 𝕜 E
  let _ : NormedSpace ℝ F := NormedSpace.restrictScalars ℝ 𝕜 F
  let f'R : E → E →L[ℝ] F := fun x ↦ (f' x).restrictScalars ℝ
  let f''R : E →L[ℝ] E →L[ℝ] F := f''.bilinearRestrictScalars ℝ
  have hfR : ∀ᶠ y in 𝓝 x, HasFDerivAt f (f'R y) y := by
    filter_upwards [hf] with y hy using HasFDerivAt.restrictScalars ℝ hy
  have : HasFDerivAt f'R f''R x := by
    simp only [hasFDerivAt_iff_tendsto] at hx ⊢
    exact hx
  change f''R v w = f''R w v
  exact second_derivative_symmetric_of_eventually_of_real hfR this v w

Goal state after:
Module: Mathlib.Analysis.Calculus.IteratedDeriv.FaaDiBruno

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : NontriviallyNormedField 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
g : 𝕜 → E
f : 𝕜 → 𝕜
s t : Set 𝕜
x : 𝕜
hg : ContDiffWithinAt 𝕜 3 g t (f x)
hf : ContDiffWithinAt 𝕜 3 f s x
ht : UniqueDiffOn 𝕜 t
hs : UniqueDiffOn 𝕜 s
hx : x ∈ s
hst : MapsTo f s t
⊢ iteratedDerivWithin 3 (g ∘ f) s x =
    derivWithin f s x ^ 3 • iteratedDerivWithin 3 g t (f x) +
        3 • iteratedDerivWithin 2 f s x • derivWithin f s x • iteratedDerivWithin 2 g t (f x) +
      iteratedDerivWithin 3 f s x • derivWithin g t (f x)

Tactic:
rw [iteratedDerivWithin_vcomp_three hg hf ht hs hx hst]
  simp [← toSpanSingleton_derivWithin, mul_smul, smul_comm (iteratedDerivWithin 2 f s x),
        iteratedFDerivWithin_apply_eq_iteratedDerivWithin_mul_prod]
  abel

Goal state after:
Module: Mathlib.Analysis.Calculus.IteratedDeriv.FaaDiBruno

Goal state before:
pp: 𝕜 : Type u_1
inst✝ : NontriviallyNormedField 𝕜
g f : 𝕜 → 𝕜
s t : Set 𝕜
x : 𝕜
hg : ContDiffWithinAt 𝕜 2 g t (f x)
hf : ContDiffWithinAt 𝕜 2 f s x
ht : UniqueDiffOn 𝕜 t
hs : UniqueDiffOn 𝕜 s
hx : x ∈ s
hst : MapsTo f s t
⊢ iteratedDerivWithin 2 (g ∘ f) s x =
    iteratedDerivWithin 2 g t (f x) * derivWithin f s x ^ 2 + derivWithin g t (f x) * iteratedDerivWithin 2 f s x

Tactic:
by
  rw [iteratedDerivWithin_scomp_two hg hf ht hs hx hst]
  simp only [smul_eq_mul, mul_comm]

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

Goal state before:
pp: 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
hg1 : IntervalIntegrable g volume (sInf (f '' [[a, b]])) (sSup (f '' [[a, b]]))
hg2 : IntegrableOn (fun x ↦ f' x • (g ∘ f) x) [[a, b]] volume
hE : CompleteSpace E
h_cont : ContinuousOn (fun u ↦ ∫ (t : ℝ) in f a..f u, g t) [[a, b]]
x : ℝ
hx : x ∈ Ioo (min a b) (max a b)
c : ℝ
hc : c ∈ Ioo (min a b) x
d : ℝ
hd : d ∈ Ioo x (max a b)
cdsub : [[c, d]] ⊆ Ioo (min a b) (max a b)
J : Set ℝ := [[sInf (f '' [[c, d]]), sSup (f '' [[c, d]])]]
hg_cont : ContinuousOn g J
hJ : f '' [[c, d]] = J
h2x : f x ∈ J
h2g : IntervalIntegrable g volume (f a) (f x)
h3g : StronglyMeasurableAtFilter g (𝓝[J] f x) volume
this✝ : Fact (f x ∈ J)
this : HasDerivWithinAt (fun u ↦ ∫ (x : ℝ) in f a..u, g x) (g (f x)) J (f x)
⊢ HasDerivWithinAt (fun u ↦ ∫ (t : ℝ) in f a..f u, g t) (f' x • (g ∘ f) x) (Ioi x) x

Tactic:
refine (this.scomp x ((hff' x hx).Ioo_of_Ioi hd.1) ?_).Ioi_of_Ioo hd.1

Goal state after:
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
hg1 : IntervalIntegrable g volume (sInf (f '' [[a, b]])) (sSup (f '' [[a, b]]))
hg2 : IntegrableOn (fun x ↦ f' x • (g ∘ f) x) [[a, b]] volume
hE : CompleteSpace E
h_cont : ContinuousOn (fun u ↦ ∫ (t : ℝ) in f a..f u, g t) [[a, b]]
x : ℝ
hx : x ∈ Ioo (min a b) (max a b)
c : ℝ
hc : c ∈ Ioo (min a b) x
d : ℝ
hd : d ∈ Ioo x (max a b)
cdsub : [[c, d]] ⊆ Ioo (min a b) (max a b)
J : Set ℝ := [[sInf (f '' [[c, d]]), sSup (f '' [[c, d]])]]
hg_cont : ContinuousOn g J
hJ : f '' [[c, d]] = J
h2x : f x ∈ J
h2g : IntervalIntegrable g volume (f a) (f x)
h3g : StronglyMeasurableAtFilter g (𝓝[J] f x) volume
this✝ : Fact (f x ∈ J)
this : HasDerivWithinAt (fun u ↦ ∫ (x : ℝ) in f a..u, g x) (g (f x)) J (f x)
⊢ MapsTo f (Ioo x d) J
Module: Mathlib.MeasureTheory.Function.JacobianOneDim

Goal state before:
pp: 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
H' : IntegrableOn (fun x ↦ f' x • g (f x)) s volume
a b c : Set ℝ
h_union : a ∪ (b ∪ c) = s
ha : MeasurableSet a
hb : MeasurableSet b
hc : MeasurableSet c
h_disj : Disjoint a (b ∪ c)
h_disj' : Disjoint b c
a_count : a.Countable
fb_count : (f '' b).Countable
deriv_b : ∀ x ∈ b, f' x = 0
deriv_c : ∀ x ∈ c, 0 ≤ f' x
inj_c : InjOn f c
a_s : a ⊆ s
bc_s : b ∪ c ⊆ s
b_s : b ⊆ s
c_s : c ⊆ s
this : ∫ (x : ℝ) in a, f' x • g (f x) = 0
⊢ ∫ (x : ℝ) in s, f' x • g (f x) = ∫ (x : ℝ) in c, f' x • g (f x)

Tactic:
rw [← h_union, setIntegral_union h_disj (hb.union hc) (H'.mono_set a_s) (H'.mono_set bc_s),
      this, zero_add]

Goal state after:
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
H' : IntegrableOn (fun x ↦ f' x • g (f x)) s volume
a b c : Set ℝ
h_union : a ∪ (b ∪ c) = s
ha : MeasurableSet a
hb : MeasurableSet b
hc : MeasurableSet c
h_disj : Disjoint a (b ∪ c)
h_disj' : Disjoint b c
a_count : a.Countable
fb_count : (f '' b).Countable
deriv_b : ∀ x ∈ b, f' x = 0
deriv_c : ∀ x ∈ c, 0 ≤ f' x
inj_c : InjOn f c
a_s : a ⊆ s
bc_s : b ∪ c ⊆ s
b_s : b ⊆ s
c_s : c ⊆ s
this : ∫ (x : ℝ) in a, f' x • g (f x) = 0
⊢ ∫ (x : ℝ) in b ∪ c, f' x • g (f x) ∂volume = ∫ (x : ℝ) in c, f' x • g (f x)
Module: Mathlib.MeasureTheory.Function.JacobianOneDim

Goal state before:
pp: 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
H' : IntegrableOn (fun x ↦ f' x • g (f x)) s volume
a b c : Set ℝ
h_union : a ∪ (b ∪ c) = s
ha : MeasurableSet a
hb : MeasurableSet b
hc : MeasurableSet c
h_disj : Disjoint a (b ∪ c)
h_disj' : Disjoint b c
a_count : a.Countable
fb_count : (f '' b).Countable
deriv_b : ∀ x ∈ b, f' x = 0
deriv_c : ∀ x ∈ c, 0 ≤ f' x
inj_c : InjOn f c
a_s : a ⊆ s
bc_s : b ∪ c ⊆ s
b_s : b ⊆ s
c_s : c ⊆ s
I : ∫ (x : ℝ) in s, f' x • g (f x) = ∫ (x : ℝ) in c, f' x • g (f x)
J : ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in f '' c, g x
F' : ℝ → ℝ →L[ℝ] ℝ := fun x ↦ smulRight 1 (f' x)
hF' : ∀ x ∈ c, HasFDerivWithinAt f (F' x) c x
⊢ ∫ (x : ℝ) in c, f' x • g (f x) = ∫ (x : ℝ) in c, |(F' x).det| • g (f x)

Tactic:
apply setIntegral_congr_fun hc (fun x hx ↦ ?_)

Goal state after:
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
H' : IntegrableOn (fun x ↦ f' x • g (f x)) s volume
a b c : Set ℝ
h_union : a ∪ (b ∪ c) = s
ha : MeasurableSet a
hb : MeasurableSet b
hc : MeasurableSet c
h_disj : Disjoint a (b ∪ c)
h_disj' : Disjoint b c
a_count : a.Countable
fb_count : (f '' b).Countable
deriv_b : ∀ x ∈ b, f' x = 0
deriv_c : ∀ x ∈ c, 0 ≤ f' x
inj_c : InjOn f c
a_s : a ⊆ s
bc_s : b ∪ c ⊆ s
b_s : b ⊆ s
c_s : c ⊆ s
I : ∫ (x : ℝ) in s, f' x • g (f x) = ∫ (x : ℝ) in c, f' x • g (f x)
J : ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in f '' c, g x
F' : ℝ → ℝ →L[ℝ] ℝ := fun x ↦ smulRight 1 (f' x)
hF' : ∀ x ∈ c, HasFDerivWithinAt f (F' x) c x
x : ℝ
hx : x ∈ c
⊢ f' x • g (f x) = |(F' x).det| • g (f x)
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.IntegrationByParts

Goal state before:
pp: case inr
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ ∫ (x : ℝ) in a..b, f' x • g (f x) = ∫ (u : ℝ) in f a..f b, g u

Tactic:
rw [integral_of_ge hab.le, ← integral_Icc_eq_integral_Ioc,
      integral_Icc_deriv_smul_of_deriv_nonpos, integral_of_le, ← integral_Icc_eq_integral_Ioc,
      neg_neg]

Goal state after:
case inr
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ f a ≤ f b

case inr.hf
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ ContinuousOn f (Icc b a)

case inr.hff'
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ ∀ x ∈ Ioo b a, HasDerivAt f (f' x) x

case inr.hf'
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ ∀ x ∈ Ioo b a, f' x ≤ 0

case inr.hab
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ b ≤ a
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
I : ∀ (x : E) (r : ℝ), x ∈ s → 0 ≤ r → μ (f '' (s ∩ closedBall x r)) ≤ ↑m * μ (closedBall x r)
a : ℝ≥0∞
ha : 0 < a
t : Set E
r : E → ℝ
t_count : t.Countable
ts : t ⊆ s
rpos : ∀ x ∈ t, 0 < r x
st : s ⊆ ⋃ x, closedBall (↑x) (r ↑x)
μt : ∑' (x : ↑t), μ (closedBall (↑x) (r ↑x)) ≤ μ s + a
this : Encodable ↑t
⊢ μ (f '' s) ≤ μ (⋃ x, f '' (s ∩ closedBall (↑x) (r ↑x)))

Tactic:
apply measure_mono

Goal state after:
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∞ := ⋯
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
I : ∀ (x : E) (r : ℝ), x ∈ s → 0 ≤ r → μ (f '' (s ∩ closedBall x r)) ≤ ↑m * μ (closedBall x r)
a : ℝ≥0∞
ha : 0 < a
t : Set E
r : E → ℝ
t_count : t.Countable
ts : t ⊆ s
rpos : ∀ x ∈ t, 0 < r x
st : s ⊆ ⋃ x, closedBall (↑x) (r ↑x)
μt : ∑' (x : ↑t), μ (closedBall (↑x) (r ↑x)) ≤ μ s + a
this : Encodable ↑t
⊢ f '' s ⊆ ⋃ x, f '' (s ∩ closedBall (↑x) (r ↑x))
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.IntegrationByParts

Goal state before:
pp: case inr
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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
M : AntitoneOn f [[a, b]]
hab : b < a
⊢ ∫ (x : ℝ) in a..b, f' x • g (f x) = ∫ (u : ℝ) in f a..f b, g u

Tactic:
· rw [integral_of_ge hab.le, ← integral_Icc_eq_integral_Ioc,
      integral_Icc_deriv_smul_of_deriv_nonpos, integral_of_le, ← integral_Icc_eq_integral_Ioc,
      neg_neg]
    · apply M right_mem_uIcc left_mem_uIcc hab.le
    · rwa [uIcc_of_ge hab.le] at hf
    · grind
    · grind
    · exact hab.le

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

Goal state before:
pp: 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), HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo (min a b) (max a b), f' x ≤ 0
⊢ ∫ (x : ℝ) in a..b, f' x • (g ∘ f) x = ∫ (u : ℝ) in f a..f b, g u

Tactic:
by
  have M : AntitoneOn f (uIcc a b) := by
    apply antitoneOn_of_deriv_nonpos (convex_uIcc a b) hf
    · rw [uIcc, interior_Icc]
      exact fun z hz ↦ (hff' z hz).differentiableAt.differentiableWithinAt
    · rw [uIcc, interior_Icc]
      intro z hz
      simpa [(hff' z hz).deriv] using hf' z hz
  simp only [Function.comp_apply]
  rcases le_or_gt a b with hab | hab
  · rw [integral_of_le hab, ← integral_Icc_eq_integral_Ioc,
      integral_Icc_deriv_smul_of_deriv_nonpos, integral_of_ge, ← integral_Icc_eq_integral_Ioc]
    · apply M left_mem_uIcc right_mem_uIcc hab
    · rwa [uIcc_of_le hab] at hf
    · grind
    · grind
    · exact hab
  · rw [integral_of_ge hab.le, ← integral_Icc_eq_integral_Ioc,
      integral_Icc_deriv_smul_of_deriv_nonpos, integral_of_le, ← integral_Icc_eq_integral_Ioc,
      neg_neg]
    · apply M right_mem_uIcc left_mem_uIcc hab.le
    · rwa [uIcc_of_ge hab.le] at hf
    · grind
    · grind
    · exact hab.le

Goal state after:
Module: Mathlib.Analysis.Calculus.LocalExtr.Polynomial

Goal state before:
pp: case h
p : ℝ[X]
x : ℝ
hx : x ∈ (derivative p).roots.toFinset \ p.roots.toFinset
⊢ x ∈ (derivative p).roots.toFinset

Tactic:
exact (Finset.mem_sdiff.1 hx).1

Goal state after: