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

Goal state before:
pp: case a.e'_6
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)
i : ℕ
hi : i ∈ Finset.range (n + 1)
⊢ D ^ i * D ^ (n - i + 1) = D ^ (n + 1)

Tactic:
· rw [← pow_add]
        congr 1
        rw [Nat.add_succ, Nat.succ_inj]
        exact Nat.add_sub_of_le (Finset.mem_range_succ_iff.1 hi)

Goal state after:
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 : ∀ ⦃c : ℝ⦄, 0 < c → ∀ᶠ (x_1 : E) in 𝓝[interior s] x, ‖f' x_1 - f' x - f'' (x_1 - x)‖ ≤ c * ‖x_1 - x‖
v w : E
hv : x + v ∈ interior s
hw : x + v + w ∈ interior s
ε : ℝ
εpos : 0 < ε
δ : ℝ
δpos : δ > 0
sδ : Metric.ball x δ ∩ interior s ⊆ {x_1 | (fun x_2 ↦ ‖f' x_2 - f' x - f'' (x_2 - x)‖ ≤ ε * ‖x_2 - x‖) x_1}
E1 : ∀ᶠ (h : ℝ) in 𝓝[>] 0, h * (‖v‖ + ‖w‖) < δ
E2 : ∀ᶠ (h : ℝ) in 𝓝[>] 0, h < 1
h : ℝ
hδ : h * (‖v‖ + ‖w‖) < δ
h_lt_1 : h < 1
hpos : 0 < h
xt_mem : ∀ t ∈ Icc 0 1, x + h • v + (t * h) • w ∈ interior s
g : ℝ → F :=
  fun t ↦ f (x + h • v + (t * h) • w) - (t * h) • (f' x) w - (t * h ^ 2) • (f'' v) w - ((t * h) ^ 2 / 2) • (f'' w) w
g' : ℝ → F :=
  fun t ↦ (f' (x + h • v + (t * h) • w)) (h • w) - h • (f' x) w - h ^ 2 • (f'' v) w - (t * h ^ 2) • (f'' w) w
hg' : g' = fun t ↦ (f' (x + h • v + (t * h) • w)) (h • w) - h • (f' x) w - h ^ 2 • (f'' v) w - (t * h ^ 2) • (f'' w) w
g_deriv : ∀ t ∈ Icc 0 1, HasDerivWithinAt g (g' t) (Icc 0 1) t
t : ℝ
ht : t ∈ Ico 0 1
I : ‖h • v + (t * h) • w‖ ≤ h * (‖v‖ + ‖w‖)
⊢ (f' (x + h • v + (t * h) • w)) (h • w) - h • (f' x) w - h ^ 2 • (f'' v) w - (t * h ^ 2) • (f'' w) w =
    (f' (x + h • v + (t * h) • w) - f' x - f'' (h • v + (t * h) • w)) (h • w)

Tactic:
simp only [sub_apply, add_apply, smul_apply, map_add, map_smul]

Goal state after:
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 : ∀ ⦃c : ℝ⦄, 0 < c → ∀ᶠ (x_1 : E) in 𝓝[interior s] x, ‖f' x_1 - f' x - f'' (x_1 - x)‖ ≤ c * ‖x_1 - x‖
v w : E
hv : x + v ∈ interior s
hw : x + v + w ∈ interior s
ε : ℝ
εpos : 0 < ε
δ : ℝ
δpos : δ > 0
sδ : Metric.ball x δ ∩ interior s ⊆ {x_1 | (fun x_2 ↦ ‖f' x_2 - f' x - f'' (x_2 - x)‖ ≤ ε * ‖x_2 - x‖) x_1}
E1 : ∀ᶠ (h : ℝ) in 𝓝[>] 0, h * (‖v‖ + ‖w‖) < δ
E2 : ∀ᶠ (h : ℝ) in 𝓝[>] 0, h < 1
h : ℝ
hδ : h * (‖v‖ + ‖w‖) < δ
h_lt_1 : h < 1
hpos : 0 < h
xt_mem : ∀ t ∈ Icc 0 1, x + h • v + (t * h) • w ∈ interior s
g : ℝ → F :=
  fun t ↦ f (x + h • v + (t * h) • w) - (t * h) • (f' x) w - (t * h ^ 2) • (f'' v) w - ((t * h) ^ 2 / 2) • (f'' w) w
g' : ℝ → F :=
  fun t ↦ (f' (x + h • v + (t * h) • w)) (h • w) - h • (f' x) w - h ^ 2 • (f'' v) w - (t * h ^ 2) • (f'' w) w
hg' : g' = fun t ↦ (f' (x + h • v + (t * h) • w)) (h • w) - h • (f' x) w - h ^ 2 • (f'' v) w - (t * h ^ 2) • (f'' w) w
g_deriv : ∀ t ∈ Icc 0 1, HasDerivWithinAt g (g' t) (Icc 0 1) t
t : ℝ
ht : t ∈ Ico 0 1
I : ‖h • v + (t * h) • w‖ ≤ h * (‖v‖ + ‖w‖)
⊢ h • (f' (x + h • v + (t * h) • w)) w - h • (f' x) w - h ^ 2 • (f'' v) w - (t * h ^ 2) • (f'' w) w =
    h • ((f' (x + h • v + (t * h) • w)) w - (f' x) w - (h • (f'' v) w + (t * h) • (f'' w) w))
Module: Mathlib.Analysis.Calculus.FDeriv.Norm

Goal state before:
pp: case e'_11
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : StrongDual ℝ E
x : E
t : ℝ
ht : t ≠ 0
h : HasStrictFDerivAt (fun x ↦ ‖x‖) f x
h1 : HasStrictFDerivAt (fun y ↦ t⁻¹ • y) (t⁻¹ • ContinuousLinearMap.id ℝ E) (t • x)
h2 : HasStrictFDerivAt (fun y ↦ |t| * ‖y‖) (|t| • f) (t⁻¹ • t • x)
x✝ : E
⊢ ‖x✝‖ = |t| * ‖t⁻¹ • x✝‖

pp: case e'_12
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : StrongDual ℝ E
x : E
t : ℝ
ht : t ≠ 0
h : HasStrictFDerivAt (fun x ↦ ‖x‖) f x
h1 : HasStrictFDerivAt (fun y ↦ t⁻¹ • y) (t⁻¹ • ContinuousLinearMap.id ℝ E) (t • x)
h2 : HasStrictFDerivAt (fun y ↦ |t| * ‖y‖) (|t| • f) (t⁻¹ • t • x)
e_8✝ : instAddCommGroup = normedAddCommGroup.toAddCommGroup
e_9✝ : Semiring.toModule ≍ RCLike.toInnerProductSpaceReal.toModule
⊢ ↑(SignType.sign t) • f = (|t| • f) ∘SL (t⁻¹ • ContinuousLinearMap.id ℝ E)

Tactic:
· rw [norm_smul, ← mul_assoc, norm_eq_abs, ← abs_mul, mul_inv_cancel₀ ht, abs_one, one_mul]

Goal state after:
case e'_12
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : StrongDual ℝ E
x : E
t : ℝ
ht : t ≠ 0
h : HasStrictFDerivAt (fun x ↦ ‖x‖) f x
h1 : HasStrictFDerivAt (fun y ↦ t⁻¹ • y) (t⁻¹ • ContinuousLinearMap.id ℝ E) (t • x)
h2 : HasStrictFDerivAt (fun y ↦ |t| * ‖y‖) (|t| • f) (t⁻¹ • t • x)
e_8✝ : instAddCommGroup = normedAddCommGroup.toAddCommGroup
e_9✝ : Semiring.toModule ≍ RCLike.toInnerProductSpaceReal.toModule
⊢ ↑(SignType.sign t) • f = (|t| • f) ∘SL (t⁻¹ • ContinuousLinearMap.id ℝ E)
Module: Mathlib.Analysis.Calculus.Gradient.Basic

Goal state before:
pp: 𝕜 : Type u_1
F : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup F
inst✝¹ : InnerProductSpace 𝕜 F
inst✝ : CompleteSpace F
f : F → 𝕜
x y : F
s : Set F
⊢ (starRingEnd 𝕜) ⟪gradientWithin f s y, x⟫ = (starRingEnd 𝕜) ((fderivWithin 𝕜 f s y) x)

Tactic:
inner_gradientWithin_left

Goal state after:
𝕜 : Type u_1
F : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup F
inst✝¹ : InnerProductSpace 𝕜 F
inst✝ : CompleteSpace F
f : F → 𝕜
x y : F
s : Set F
⊢ (starRingEnd 𝕜) ((fderivWithin 𝕜 f s y) x) = (starRingEnd 𝕜) ((fderivWithin 𝕜 f s y) x)
Module: Mathlib.Analysis.Calculus.LHopital

Goal state before:
pp: 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
hg' : ∀ x ∈ Ioo a b, g' x ≠ 0
hfa : Tendsto f (𝓝[>] a) (𝓝 0)
hga : Tendsto g (𝓝[>] a) (𝓝 0)
hdiv : Tendsto (fun x ↦ f' x / g' x) (𝓝[>] a) l
sub : ∀ x ∈ Ioo a b, Ioo a x ⊆ Ioo a b
x : ℝ
hx : x ∈ Ioo a b
h : g x = 0
this : Tendsto g (𝓝[<] x) (𝓝 0)
y : ℝ
hyx : y ∈ Ioo a x
hy : g' y = 0
⊢ False

Tactic:
exact hg' y (sub x hx hyx) hy

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

Goal state before:
pp: E : Type u_1
F : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : FiniteDimensional ℝ E
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace ℝ F
inst✝ : SecondCountableTopology F
f : E → F
s : Set E
f' : E → E →L[ℝ] F
hf' : ∀ x ∈ s, HasFDerivWithinAt f (f' x) s x
r : (E →L[ℝ] F) → ℝ≥0
rpos : ∀ (A : E →L[ℝ] F), r A ≠ 0
hs : s.Nonempty
T : Set ↑s
T_count : T.Countable
hT : ⋃ x ∈ T, ball (f' ↑x) ↑(r (f' ↑x)) = ⋃ x, ball (f' ↑x) ↑(r (f' ↑x))
u : ℕ → ℝ
left✝ : StrictAnti u
u_pos : ∀ (n : ℕ), 0 < u n
u_lim : Tendsto u atTop (𝓝 0)
M : ℕ → ↑T → Set E :=
  fun n z ↦ {x | x ∈ s ∧ ∀ y ∈ s ∩ ball x (u n), ‖f y - f x - (f' ↑↑z) (y - x)‖ ≤ ↑(r (f' ↑↑z)) * ‖y - x‖}
x : E
xs : x ∈ s
⊢ ∃ z ∈ T, f' x ∈ ball (f' ↑z) ↑(r (f' ↑z))

Tactic:
by
      have : f' x ∈ ⋃ z ∈ T, ball (f' (z : E)) (r (f' z)) := by
        rw [hT]
        refine mem_iUnion.2 ⟨⟨x, xs⟩, ?_⟩
        simpa only [mem_ball, Subtype.coe_mk, dist_self] using! (rpos (f' x)).bot_lt
      rwa [mem_iUnion₂, bex_def] at this

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

Goal state before:
pp: a : ℝ
l : Filter ℝ
f f' g g' : ℝ → ℝ
s : Set ℝ
hs : Convex ℝ s
hff' : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, HasDerivWithinAt f (f' x) (s \ {a}) x
hgg' : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, HasDerivWithinAt g (g' x) (s \ {a}) x
hg' : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, g' x ≠ 0
hfa : Tendsto f (𝓝[s \ {a}] a) (𝓝 0)
hga : Tendsto g (𝓝[s \ {a}] a) (𝓝 0)
hdiv : Tendsto (fun x ↦ f' x / g' x) (𝓝[s \ {a}] a) l
has : a ∈ closure s
h : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, s \ {a} ∈ 𝓝 x
⊢ Tendsto (fun x ↦ f x / g x) (𝓝[s \ {a}] a) l

Tactic:
replace hff' := h.mp <| hff'.mono fun _ h ↦ h.hasDerivAt

Goal state after:
a : ℝ
l : Filter ℝ
f f' g g' : ℝ → ℝ
s : Set ℝ
hs : Convex ℝ s
hgg' : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, HasDerivWithinAt g (g' x) (s \ {a}) x
hg' : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, g' x ≠ 0
hfa : Tendsto f (𝓝[s \ {a}] a) (𝓝 0)
hga : Tendsto g (𝓝[s \ {a}] a) (𝓝 0)
hdiv : Tendsto (fun x ↦ f' x / g' x) (𝓝[s \ {a}] a) l
has : a ∈ closure s
h : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, s \ {a} ∈ 𝓝 x
hff' : ∀ᶠ (x : ℝ) in 𝓝[s \ {a}] a, HasDerivAt f (f' x) x
⊢ Tendsto (fun x ↦ f x / g x) (𝓝[s \ {a}] a) l
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), 0 ≤ f' x
⊢ IntervalIntegrable (fun x ↦ f' x • (g ∘ f) x) volume a b ↔ IntervalIntegrable g volume (f a) (f b)

Tactic:
by
  have M : MonotoneOn f (uIcc a b) := by
    apply monotoneOn_of_deriv_nonneg (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 [intervalIntegrable_iff_integrableOn_Icc_of_le hab,
      integrableOn_Icc_deriv_smul_iff_of_deriv_nonneg,
      intervalIntegrable_iff_integrableOn_Icc_of_le]
    · apply M left_mem_uIcc right_mem_uIcc hab
    · rwa [uIcc_of_le hab] at hf
    · grind
    · grind
    · exact hab
  · rw [IntervalIntegrable.symm_iff, intervalIntegrable_iff_integrableOn_Icc_of_le hab.le,
      integrableOn_Icc_deriv_smul_iff_of_deriv_nonneg,
      IntervalIntegrable.symm_iff, intervalIntegrable_iff_integrableOn_Icc_of_le]
    · 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.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
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
⊢ ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in s, f' x • g (f x)

Tactic:
have bc_s : b ∪ c ⊆ s := by rw [← h_union]; exact subset_union_right

Goal state after:
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
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
⊢ ∫ (x : ℝ) in f '' s, g x = ∫ (x : ℝ) in s, 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
f f' : ℝ → ℝ
a b : ℝ
g : ℝ → F
hf : ContinuousOn f (Icc a b)
hff' : ∀ x ∈ Ioo a b, HasDerivAt f (f' x) x
hf' : ∀ x ∈ Ioo a b, 0 ≤ f' x
hab : a ≤ b
⊢ ∫ (x : ℝ) in Icc a b, f' x • g (f x) = ∫ (u : ℝ) in Icc (f a) (f b), g u

Tactic:
have M : MonotoneOn f (Icc a b) := by
    apply monotoneOn_of_deriv_nonneg (convex_Icc a b) hf
    · rw [interior_Icc]
      exact fun z hz ↦ (hff' z hz).differentiableAt.differentiableWithinAt
    · rw [interior_Icc]
      intro z hz
      simpa [(hff' z hz).deriv] using hf' z hz
  have A : ∫ u in Icc (f a) (f b), g u = ∫ u in f '' (Ioo a b), g u := by
    apply setIntegral_congr_set
    rw [← hf.image_Icc_of_monotoneOn hab M]
    refine ae_eq_set.2 ⟨?_, by simp [show f '' Ioo a b \ f '' Icc a b = ∅ by grind]⟩
    have : f '' (Icc a b) \ f '' Ioo a b ⊆ {f a, f b} := by grind
    apply measure_mono_null this
    apply Finite.measure_zero (by simp)
  rw [A, integral_Icc_eq_integral_Ioo,
    integral_image_eq_integral_deriv_smul_of_monotoneOn measurableSet_Ioo]
  · exact fun z hz ↦ (hff' z hz).hasDerivWithinAt
  · exact M.mono Ioo_subset_Icc_self

Goal state after:
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
⊢ IntervalIntegrable (fun x ↦ f' x • g (f x)) volume a b ↔ IntervalIntegrable g volume (f a) (f b)

Tactic:
· rw [IntervalIntegrable.symm_iff, intervalIntegrable_iff_integrableOn_Icc_of_le hab.le,
      integrableOn_Icc_deriv_smul_iff_of_deriv_nonpos,
      intervalIntegrable_iff_integrableOn_Icc_of_le]
    · 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.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
⊢ ‖f' x - A‖₊ ≤ δ

Tactic:
apply ContinuousLinearMap.opNorm_le_bound _ δ.2 fun z => ?_

Goal state after:
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
⊢ ‖(f' x - A) z‖ ≤ ↑δ * ‖z‖
Module: Mathlib.MeasureTheory.Integral.IntegralEqImproper

Goal state before:
pp: E : Type u_1
f f' : ℝ → E
a : ℝ
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : CompleteSpace E
hderiv : ∀ x ∈ Iic a, HasDerivAt f (f' x) x
f'int : IntegrableOn f' (Iic a) volume
g : ℝ → E := ⋯
hdg : ∀ x ∈ Ioi (-a), HasDerivAt g (-f' (-x)) x
⊢ IntegrableOn (fun x ↦ -f' (-x)) (Ioi (-a)) volume

Tactic:
exact ((MeasurePreserving.integrableOn_comp_preimage (Measure.measurePreserving_neg _)
      (Homeomorph.neg ℝ).measurableEmbedding).2 f'int.neg).mono_set (by simp)

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

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁹ : NontriviallyNormedField 𝕜
inst✝⁸ : LocallyCompactSpace 𝕜
E : Type u_2
inst✝⁷ : NormedAddCommGroup E
inst✝⁶ : NormedSpace 𝕜 E
inst✝⁵ : MeasurableSpace E
inst✝⁴ : OpensMeasurableSpace E
F : Type u_3
inst✝³ : NormedAddCommGroup F
inst✝² : NormedSpace 𝕜 F
inst✝¹ : CompleteSpace F
f : E → F
inst✝ : SecondCountableTopology E
hf : Continuous f
this✝¹ : MeasurableSpace 𝕜 := borel 𝕜
this✝ : BorelSpace 𝕜
g : E × E → 𝕜 → F := fun p t ↦ f (p.1 + t • p.2)
this : Continuous (Function.uncurry g)
⊢ StronglyMeasurable fun p ↦ lineDeriv 𝕜 f p.1 p.2

Tactic:
exact (stronglyMeasurable_deriv_with_param this).comp_measurable measurable_prodMk_right

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
I : r * ‖(f' x - A) a‖ ≤ r * (↑δ + ε) * (‖z‖ + ε)
⊢ ‖(f' x - A) z‖ = ‖(f' x - A) a + (f' x - A) (z - a)‖

Tactic:
by
      congr 1
      simp only [FunLike.coe_sub, map_sub, Pi.sub_apply]
      abel

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

Goal state before:
pp: 𝕜 : Type u_1
inst✝³ : RCLike 𝕜
μ : Measure ℝ
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : NormedSpace 𝕜 E
a b : ℝ
bound : ℝ → ℝ
F F' : 𝕜 → ℝ → E
x₀ : 𝕜
s : Set 𝕜
hs : s ∈ 𝓝 x₀
hF_meas : ∀ᶠ (x : 𝕜) in 𝓝 x₀, AEStronglyMeasurable (F x) (μ.restrict (Ι a b))
hF'_meas : AEStronglyMeasurable (F' x₀) (μ.restrict (Ι a b))
h_bound : ∀ᵐ (x : ℝ) ∂μ.restrict (Ι a b), ∀ x_1 ∈ s, ‖F' x_1 x‖ ≤ bound x
h_diff : ∀ᵐ (x : ℝ) ∂μ.restrict (Ι a b), ∀ x_1 ∈ s, HasDerivAt (fun x_2 ↦ F x_2 x) (F' x_1 x) x_1
hF_int : IntegrableOn (F x₀) (Ι a b) μ
bound_integrable : IntegrableOn bound (Ι a b) μ
⊢ IntegrableOn (F' x₀) (Ι a b) μ ∧
    HasDerivAt (fun x ↦ (if a ≤ b then 1 else -1) • ∫ (t : ℝ) in Ι a b, F x t ∂μ)
      ((if a ≤ b then 1 else -1) • ∫ (t : ℝ) in Ι a b, F' x₀ t ∂μ) x₀

Tactic:
have := hasDerivAt_integral_of_dominated_loc_of_deriv_le hs hF_meas hF_int hF'_meas h_bound
    bound_integrable h_diff

Goal state after:
𝕜 : Type u_1
inst✝³ : RCLike 𝕜
μ : Measure ℝ
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : NormedSpace 𝕜 E
a b : ℝ
bound : ℝ → ℝ
F F' : 𝕜 → ℝ → E
x₀ : 𝕜
s : Set 𝕜
hs : s ∈ 𝓝 x₀
hF_meas : ∀ᶠ (x : 𝕜) in 𝓝 x₀, AEStronglyMeasurable (F x) (μ.restrict (Ι a b))
hF'_meas : AEStronglyMeasurable (F' x₀) (μ.restrict (Ι a b))
h_bound : ∀ᵐ (x : ℝ) ∂μ.restrict (Ι a b), ∀ x_1 ∈ s, ‖F' x_1 x‖ ≤ bound x
h_diff : ∀ᵐ (x : ℝ) ∂μ.restrict (Ι a b), ∀ x_1 ∈ s, HasDerivAt (fun x_2 ↦ F x_2 x) (F' x_1 x) x_1
hF_int : IntegrableOn (F x₀) (Ι a b) μ
bound_integrable : IntegrableOn bound (Ι a b) μ
this :
  Integrable (F' x₀) (μ.restrict (Ι a b)) ∧
    HasDerivAt (fun n ↦ ∫ (a : ℝ) in Ι a b, F n a ∂μ) (∫ (a : ℝ) in Ι a b, F' x₀ a ∂μ) x₀
⊢ IntegrableOn (F' x₀) (Ι a b) μ ∧
    HasDerivAt (fun x ↦ (if a ≤ b then 1 else -1) • ∫ (t : ℝ) in Ι a b, F x t ∂μ)
      ((if a ≤ b then 1 else -1) • ∫ (t : ℝ) in Ι a b, F' x₀ t ∂μ) x₀
Module: Mathlib.Geometry.Manifold.HasGroupoid

Goal state before:
pp: H : Type u
M : Type u_2
inst✝³ : TopologicalSpace H
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
G : StructureGroupoid H
inst✝ : ClosedUnderRestriction G
e e' : OpenPartialHomeomorph M H
he : e ∈ StructureGroupoid.maximalAtlas M G
he' : e' ∈ atlas H M
s : Set M
hs : IsOpen[inst✝²] s
⊢ IsOpen[inst✝³] (↑e '' (e.source ∩ s))

Tactic:
rw [isOpen_image_iff_of_subset_source _ inter_subset_left]

Goal state after:
H : Type u
M : Type u_2
inst✝³ : TopologicalSpace H
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
G : StructureGroupoid H
inst✝ : ClosedUnderRestriction G
e e' : OpenPartialHomeomorph M H
he : e ∈ StructureGroupoid.maximalAtlas M G
he' : e' ∈ atlas H M
s : Set M
hs : IsOpen[inst✝²] s
⊢ IsOpen[inst✝²] (e.source ∩ s)
Module: Mathlib.Geometry.Manifold.HasGroupoid

Goal state before:
pp: H : Type u
M : Type u_2
inst✝³ : TopologicalSpace H
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
G : StructureGroupoid H
inst✝ : ClosedUnderRestriction G
e e' : OpenPartialHomeomorph M H
he : e ∈ StructureGroupoid.maximalAtlas M G
he' : e' ∈ atlas H M
s : Set M
hs : IsOpen[inst✝²] s
hs'' : IsOpen[inst✝³] (↑e' '' (e'.source ∩ s))
⊢ IsOpen[inst✝³] (e'.target ∩ ↑e'.symm ⁻¹' s)

Tactic:
← image_source_inter_eq'

Goal state after:
H : Type u
M : Type u_2
inst✝³ : TopologicalSpace H
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
G : StructureGroupoid H
inst✝ : ClosedUnderRestriction G
e e' : OpenPartialHomeomorph M H
he : e ∈ StructureGroupoid.maximalAtlas M G
he' : e' ∈ atlas H M
s : Set M
hs : IsOpen[inst✝²] s
hs'' : IsOpen[inst✝³] (↑e' '' (e'.source ∩ s))
⊢ IsOpen[inst✝³] (↑e' '' (e'.source ∩ s))
Module: Mathlib.Geometry.Manifold.HasGroupoid

Goal state before:
pp: H : Type u
H' : Type u_1
M : Type u_2
M' : Type u_3
M'' : Type u_4
inst✝⁶ : TopologicalSpace H
inst✝⁵ : TopologicalSpace M
inst✝⁴ : ChartedSpace H M
inst✝³ : TopologicalSpace M'
inst✝² : TopologicalSpace M''
G : StructureGroupoid H
inst✝¹ : ChartedSpace H M'
inst✝ : ChartedSpace H M''
e : Structomorph G M M'
⊢ ∀ (c : OpenPartialHomeomorph M' H) (c' : OpenPartialHomeomorph M H),
    c ∈ atlas H M' → c' ∈ atlas H M → c.symm ≫ₕ e.symm.toOpenPartialHomeomorph ≫ₕ c' ∈ G

Tactic:
intro c c' hc hc'
      have : (c'.symm ≫ₕ e.toHomeomorph.toOpenPartialHomeomorph ≫ₕ c).symm ∈ G :=
        G.symm (e.mem_groupoid c' c hc' hc)
      rwa [trans_symm_eq_symm_trans_symm, trans_symm_eq_symm_trans_symm, symm_symm, trans_assoc]
        at this

Goal state after:
Module: Mathlib.Geometry.Manifold.IsManifold.ExtChartAt

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
M : Type u_3
H : Type u_4
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : TopologicalSpace H
inst✝ : TopologicalSpace M
f : OpenPartialHomeomorph M H
I : ModelWithCorners 𝕜 E H
⊢ (f.extend I).source = f.source

Tactic:
rw [extend, PartialEquiv.trans_source, I.source_eq, preimage_univ, inter_univ]

Goal state after:
Module: Mathlib.Geometry.Manifold.IsManifold.ExtChartAt

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
M : Type u_3
H : Type u_4
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : TopologicalSpace H
inst✝ : TopologicalSpace M
f : OpenPartialHomeomorph M H
I : ModelWithCorners 𝕜 E H
x : M
hx : x ∈ f.source
⊢ ↑I '' f.target ∈ 𝓝[range ↑I] ↑(f.extend I) x

Tactic:
by
  rw [← f.map_extend_nhds hx, Filter.mem_map,
    f.extend_coe, Set.preimage_comp, I.preimage_image f.target]
  exact (f.continuousAt hx).preimage_mem_nhds (f.open_target.mem_nhds (f.map_source hx))

Goal state after: