mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Probability.Moments.Variance

Goal state before:

Tactic:
_ ≤ (a + b) * μ[X] - a * b - μ[X] ^ 2 := by
      rw [variance_eq_sub (memLp_of_bounded h hX.aestronglyMeasurable 2)]
      linarith
    _ = (b - μ[X]) * (μ[X] - a) := by ring

Goal state after:
Module: Mathlib.Probability.Moments.Variance

Goal state before:
pp: case refine_2
Ω : Type u_1
mΩ : MeasurableSpace Ω
μ : Measure Ω
Ω' : Type u_3
mΩ' : MeasurableSpace Ω'
ν : Measure Ω'
inst✝¹ : IsProbabilityMeasure μ
inst✝ : IsProbabilityMeasure ν
X : Ω → ℝ
Y : Ω' → ℝ
hfμ : MemLp X 2 μ
hgν : MemLp Y 2 ν
⊢ Var[fun x ↦ X x.1; μ.prod ν] + Var[fun x ↦ Y x.2; μ.prod ν] = Var[X; μ] + Var[Y; ν]

Tactic:
· rw [measurePreserving_fst.variance_fun_comp hfμ.aemeasurable,
      measurePreserving_snd.variance_fun_comp hgν.aemeasurable]

Goal state after:
Module: Mathlib.Probability.Independence.Kernel.IndepFun

Goal state before:
pp: case refine_1
α : Type u_1
Ω : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
β : ι → Type u_8
m : (i : ι) → MeasurableSpace (β i)
f : (i : ι) → Ω → β i
S T : Finset ι
hST : Disjoint S T
hf_Indep : iIndepFun f κ μ
hf_meas : ∀ (i : ι), AEMeasurable (f i) (⇑κ ∘ₘ μ)
h : IndepFun (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) κ μ
⊢ ∀ᵐ (a : α) ∂μ, (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) =ᵐ[κ a] fun a i ↦ f (↑i) a

pp: case refine_2
α : Type u_1
Ω : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
β : ι → Type u_8
m : (i : ι) → MeasurableSpace (β i)
f : (i : ι) → Ω → β i
S T : Finset ι
hST : Disjoint S T
hf_Indep : iIndepFun f κ μ
hf_meas : ∀ (i : ι), AEMeasurable (f i) (⇑κ ∘ₘ μ)
h : IndepFun (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) κ μ
⊢ ∀ᵐ (a : α) ∂μ, (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) =ᵐ[κ a] fun a i ↦ f (↑i) a

Tactic:
· have : ∀ᵐ (a : α) ∂μ, ∀ (i : S), f i =ᵐ[κ a] (hf_meas i).mk := by
      rw [ae_all_iff]
      exact fun i ↦ Measure.ae_ae_of_ae_comp (hf_meas i).ae_eq_mk
    filter_upwards [this] with a ha
    filter_upwards [ae_all_iff.2 ha] with b hb
    ext i
    exact (hb i).symm

Goal state after:
case refine_2
α : Type u_1
Ω : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
β : ι → Type u_8
m : (i : ι) → MeasurableSpace (β i)
f : (i : ι) → Ω → β i
S T : Finset ι
hST : Disjoint S T
hf_Indep : iIndepFun f κ μ
hf_meas : ∀ (i : ι), AEMeasurable (f i) (⇑κ ∘ₘ μ)
h : IndepFun (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) κ μ
⊢ ∀ᵐ (a : α) ∂μ, (fun a i ↦ AEMeasurable.mk (f ↑i) ⋯ a) =ᵐ[κ a] fun a i ↦ f (↑i) a
Module: Mathlib.Probability.Independence.Kernel.IndepFun

Goal state before:
pp: case refine_2
α : Type u_1
Ω : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
β : ι → Type u_8
m : (i : ι) → MeasurableSpace (β i)
f : (i : ι) → Ω → β i
hf_indep : iIndepFun f κ μ
hf_meas : ∀ (i : ι), AEMeasurable (f i) (⇑κ ∘ₘ μ)
i j k l : ι
hik : i ≠ k
hil : i ≠ l
hjk : j ≠ k
hjl : j ≠ l
h :
  IndepFun (fun a ↦ (AEMeasurable.mk (f i) ⋯ a, AEMeasurable.mk (f j) ⋯ a))
    (fun a ↦ (AEMeasurable.mk (f k) ⋯ a, AEMeasurable.mk (f l) ⋯ a)) κ μ
⊢ ∀ᵐ (a : α) ∂μ, (fun a ↦ (AEMeasurable.mk (f k) ⋯ a, AEMeasurable.mk (f l) ⋯ a)) =ᵐ[κ a] fun a ↦ (f k a, f l a)

Tactic:
filter_upwards [Measure.ae_ae_of_ae_comp (hf_meas k).ae_eq_mk,
      Measure.ae_ae_of_ae_comp (hf_meas l).ae_eq_mk] with a hk hl
    filter_upwards [hk, hl] with ω hωk hωl
    rw [← hωk, ← hωl]

Goal state after:
Module: Mathlib.Probability.Independence.Kernel.IndepFun

Goal state before:
pp: α : Type u_1
Ω : Type u_2
ι : Type u_3
β : Type u_4
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
inst✝¹ : Zero β
inst✝ : One β
m : MeasurableSpace β
s : ι → Set Ω
hs : iIndepSet s κ μ
⊢ ∀ (S : Finset ι) {sets : ι → Set β},
    (∀ i ∈ S, MeasurableSet (sets i)) →
      ∀ᵐ (a : α) ∂μ,
        (κ a) (⋂ i ∈ S, ((s i).indicator fun _ω ↦ 1) ⁻¹' sets i) =
          ∏ i ∈ S, (κ a) (((s i).indicator fun _ω ↦ 1) ⁻¹' sets i)

Tactic:
rintro S π _hπ

Goal state after:
α : Type u_1
Ω : Type u_2
ι : Type u_3
β : Type u_4
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
inst✝¹ : Zero β
inst✝ : One β
m : MeasurableSpace β
s : ι → Set Ω
hs : iIndepSet s κ μ
S : Finset ι
π : ι → Set β
_hπ : ∀ i ∈ S, MeasurableSet (π i)
⊢ ∀ᵐ (a : α) ∂μ,
    (κ a) (⋂ i ∈ S, ((s i).indicator fun _ω ↦ 1) ⁻¹' π i) = ∏ i ∈ S, (κ a) (((s i).indicator fun _ω ↦ 1) ⁻¹' π i)
Module: Mathlib.Probability.Process.Filtration

Goal state before:
pp: Ω : Type u_1
ι : Type u_2
m : MeasurableSpace Ω
inst✝ : PartialOrder ι
𝓕 : Filtration ι m
this : TopologicalSpace ι := Preorder.topology ι
i : ι
⊢ (if (𝓝[>] i).NeBot then ⨅ j, ⨅ (_ : j > i), ↑𝓕 j else ↑𝓕 i) ≤ m

Tactic:
split_ifs with hi
      · obtain ⟨j, hj⟩ := (frequently_gt_nhds i).exists
        exact iInf₂_le_of_le j hj (𝓕.le j)
      · exact 𝓕.le i

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

Goal state before:
pp: α : Type u_2
inst✝¹ : MeasurableSpace α
μ : Measure α
inst✝ : IsFiniteMeasure μ
r : ℝ≥0∞
s : ℕ → Set α
hs : ∀ (n : ℕ), MeasurableSet (s n)
hr₀ : r ≠ 0
hr : ∀ (n : ℕ), r ≤ μ (s n)
M : (α → ℝ) → Set α := fun f ↦ {x | eLpNormEssSup f μ < ↑‖f x‖₊}
N : Set α := ⋃ u, M ((⋂ n ∈ u, s n).indicator 1)
hN₀ : μ N = 0
hN₁ : ∀ (u : Finset ℕ), ((⋂ n ∈ u, s n) \ N).Nonempty → 0 < μ (⋂ n ∈ u, s n)
f : ℕ → α → ℝ≥0∞ := fun n ↦ (↑(n + 1))⁻¹ • ∑ k ∈ Finset.range (n + 1), (s k).indicator 1
hfapp : ∀ (n : ℕ) (a : α), f n a = (↑(n + 1))⁻¹ * ∑ k ∈ Finset.range (n + 1), (s k).indicator 1 a
hf : ∀ (n : ℕ), Measurable (f n)
hf₁ : ∀ (n : ℕ), f n ≤ 1
hrf : ∀ (n : ℕ), r ≤ ∫⁻ (a : α), f n a ∂μ
hμ : μ ≠ 0
this : ∫⁻ (x : α), limsup (fun x_1 ↦ f x_1 x) atTop ∂μ ≤ μ univ
⊢ μ univ ≠ ∞

Tactic:
by finiteness

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

Goal state before:
pp: α : Type u_2
inst✝¹ : MeasurableSpace α
μ : Measure α
inst✝ : IsFiniteMeasure μ
r : ℝ≥0∞
s : ℕ → Set α
hs : ∀ (n : ℕ), MeasurableSet (s n)
hr₀ : r ≠ 0
hr : ∀ (n : ℕ), r ≤ μ (s n)
M : (α → ℝ) → Set α := fun f ↦ {x | eLpNormEssSup f μ < ↑‖f x‖₊}
N : Set α := ⋃ u, M ((⋂ n ∈ u, s n).indicator 1)
hN₀ : μ N = 0
hN₁ : ∀ (u : Finset ℕ), ((⋂ n ∈ u, s n) \ N).Nonempty → 0 < μ (⋂ n ∈ u, s n)
f : ℕ → α → ℝ≥0∞ := fun n ↦ (↑(n + 1))⁻¹ • ∑ k ∈ Finset.range (n + 1), (s k).indicator 1
hfapp : ∀ (n : ℕ) (a : α), f n a = (↑(n + 1))⁻¹ * ∑ k ∈ Finset.range (n + 1), (s k).indicator 1 a
hf : ∀ (n : ℕ), Measurable (f n)
hf₁ : ∀ (n : ℕ), f n ≤ 1
hrf : ∀ (n : ℕ), r ≤ ∫⁻ (a : α), f n a ∂μ
hμ : μ ≠ 0
this : ∫⁻ (x : α), limsup (fun x_1 ↦ f x_1 x) atTop ∂μ ≤ μ univ
x : α
hxN : x ∉ N
hx : r / μ univ ≤ limsup (fun x_1 ↦ f x_1 x) atTop
hxs : {n | x ∈ s n}.Finite
⊢ μ univ ≠ ∞

Tactic:
by finiteness

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

Goal state before:
pp: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
hp_top : p ≠ ∞
n : ℕ
h : ∀ {f : Fin n → α → β}, (∀ (i : Fin n), MemLp (f i) p μ) → UnifTight f p μ
f : Fin (n + 1) → α → β
hfLp : ∀ (i : Fin (n + 1)), MemLp (f i) p μ
ε : ℝ≥0
hε : 0 < ε
hε_top : ¬↑ε = ∞
g : Fin n → α → β := fun k ↦ f k.castSucc
hgLp : ∀ (i : Fin n), MemLp (g i) p μ
S : Set α
hμS : μ S ≠ ∞
hFε : ∀ (i : Fin n), eLpNorm (Sᶜ.indicator (g i)) p μ ≤ ↑ε
s : Set α
left✝ : MeasurableSet s
hμs : μ s < ∞
hfε : eLpNorm (sᶜ.indicator (f (Fin.last n))) p μ < ↑ε
⊢ μ (s ∪ S) ≠ ∞

Tactic:
by finiteness

Goal state after:
Module: Mathlib.MeasureTheory.Group.GeometryOfNumbers

Goal state before:
pp: E : Type u_1
inst✝⁶ : MeasurableSpace E
μ : Measure E
F s : Set E
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : BorelSpace E
inst✝² : FiniteDimensional ℝ E
inst✝¹ : μ.IsAddHaarMeasure
L : AddSubgroup E
inst✝ : Countable ↥L
fund : IsAddFundamentalDomain (↥L) F μ
h_symm : ∀ x ∈ s, -x ∈ s
h_conv : Convex ℝ s
h : μ F * 2 ^ finrank ℝ E < μ s
⊢ 2 ^ finrank ℝ E ≠ ∞

Tactic:
by finiteness

Goal state after:
Module: Mathlib.MeasureTheory.Group.ModularCharacter

Goal state before:
pp: G : Type u_1
inst✝⁶ : TopologicalSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : LocallyCompactSpace G
inst✝² : MeasurableSpace G
inst✝¹ : BorelSpace G
μ : Measure G
inst✝ : μ.IsHaarMeasure
g : G
ν : Measure G := haar
f : G → ℝ
f_cont : Continuous f
f_comp : HasCompactSupport ⇑{ toFun := f, continuous_toFun := f_cont }
f_nonneg : 0 ≤ { toFun := f, continuous_toFun := f_cont }
f_one : { toFun := f, continuous_toFun := f_cont } 1 ≠ 0
int_f_ne_zero : ∀ (μ₀ : Measure G) [μ₀.IsHaarMeasure], ∫ (x : G), f x ∂μ₀ ≠ 0
t : ∫ (x : G), f (x * g) ∂ν = ∫ (x : G), f (x * g) ∂ν.haarScalarFactor μ • μ
r : ↑(ν.haarScalarFactor μ) / ↑(ν.haarScalarFactor μ) = 1
⊢ ↑(ν.haarScalarFactor μ) / ↑(ν.haarScalarFactor μ) * ((∫ (x : G), f (x * g) ∂μ) / ∫ (x : G), f x ∂μ) =
    1 * ((∫ (x : G), f (x * g) ∂μ) / ∫ (x : G), f x ∂μ)

Tactic:
r

Goal state after:
G : Type u_1
inst✝⁶ : TopologicalSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : LocallyCompactSpace G
inst✝² : MeasurableSpace G
inst✝¹ : BorelSpace G
μ : Measure G
inst✝ : μ.IsHaarMeasure
g : G
ν : Measure G := haar
f : G → ℝ
f_cont : Continuous f
f_comp : HasCompactSupport ⇑{ toFun := f, continuous_toFun := f_cont }
f_nonneg : 0 ≤ { toFun := f, continuous_toFun := f_cont }
f_one : { toFun := f, continuous_toFun := f_cont } 1 ≠ 0
int_f_ne_zero : ∀ (μ₀ : Measure G) [μ₀.IsHaarMeasure], ∫ (x : G), f x ∂μ₀ ≠ 0
t : ∫ (x : G), f (x * g) ∂ν = ∫ (x : G), f (x * g) ∂ν.haarScalarFactor μ • μ
r : ↑(ν.haarScalarFactor μ) / ↑(ν.haarScalarFactor μ) = 1
⊢ 1 * ((∫ (x : G), f (x * g) ∂μ) / ∫ (x : G), f x ∂μ) = 1 * ((∫ (x : G), f (x * g) ∂μ) / ∫ (x : G), f x ∂μ)
Module: Mathlib.MeasureTheory.Group.GeometryOfNumbers

Goal state before:
pp: E : Type u_1
inst✝⁶ : MeasurableSpace E
μ : Measure E
F s : Set E
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : BorelSpace E
inst✝² : FiniteDimensional ℝ E
inst✝¹ : μ.IsAddHaarMeasure
L : AddSubgroup E
inst✝ : Countable ↥L
fund : IsAddFundamentalDomain (↥L) F μ
h_symm : ∀ x ∈ s, -x ∈ s
h_conv : Convex ℝ s
h : μ F * 2 ^ finrank ℝ E < μ s
⊢ ∃ x, x ≠ 0 ∧ ↑x ∈ s

Tactic:
by
  have h_vol : μ F < μ ((2⁻¹ : ℝ) • s) := by
    rw [addHaar_smul_of_nonneg μ (by simp : 0 ≤ (2 : ℝ)⁻¹) s,
      ← ENNReal.mul_lt_mul_iff_left (pow_ne_zero (finrank ℝ E) (two_ne_zero' _)) (by finiteness),
      mul_right_comm, ofReal_pow (by simp : 0 ≤ (2 : ℝ)⁻¹), ofReal_inv_of_pos zero_lt_two]
    simpa [← mul_pow, ENNReal.inv_mul_cancel two_ne_zero ofNat_ne_top]
  obtain ⟨x, y, hxy, h⟩ :=
    exists_pair_mem_lattice_not_disjoint_vadd fund ((h_conv.smul _).nullMeasurableSet _) h_vol
  obtain ⟨_, ⟨v, hv, rfl⟩, w, hw, hvw⟩ := Set.not_disjoint_iff.mp h
  refine ⟨x - y, sub_ne_zero.2 hxy, ?_⟩
  rw [Set.mem_inv_smul_set_iff₀ (two_ne_zero' ℝ)] at hv hw
  simp_rw [AddSubgroup.vadd_def, vadd_eq_add, add_comm _ w, ← sub_eq_sub_iff_add_eq_add, ←
    AddSubgroup.coe_sub] at hvw
  rw [← hvw, ← inv_smul_smul₀ (two_ne_zero' ℝ) (_ - _), smul_sub, sub_eq_add_neg, smul_add]
  refine h_conv hw (h_symm _ hv) ?_ ?_ ?_ <;> norm_num

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

Goal state before:
pp: p q b : ℝ
hp : 0 < p
hq : -1 < q
hb : 0 < b
⊢ ∫ (x : ℝ) in Ioi 0, b ^ (-p⁻¹ * q) * ((b ^ p⁻¹ * x) ^ q * rexp (-(b ^ p⁻¹ * x) ^ p)) =
    (b ^ p⁻¹)⁻¹ * ∫ (x : ℝ) in Ioi 0, b ^ (-p⁻¹ * q) * (x ^ q * rexp (-x ^ p))

Tactic:
rw [integral_comp_mul_left_Ioi (fun x => b ^ (-p⁻¹ * q) * (x ^ q * exp (-x ^ p))) 0,
        mul_zero, smul_eq_mul]
      all_goals positivity

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

Goal state before:
pp: α : Type u_1
inst✝² : MeasurableSpace α
A : Set α
ι : Type u_2
L : Filter ι
inst✝¹ : L.IsCountablyGenerated
As : ι → Set α
μ : Measure α
inst✝ : IsFiniteMeasure μ
A_mble : MeasurableSet A
As_mble : ∀ (i : ι), MeasurableSet (As i)
h_lim : ∀ᵐ (x : α) ∂μ, ∀ᶠ (i : ι) in L, x ∈ As i ↔ x ∈ A
⊢ μ univ ≠ ∞

Tactic:
by finiteness

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

Goal state before:
pp: E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : ℝ → E
a b : ℝ
B : ℝ → ℝ
hab : a ≤ b
hfc : ContinuousOn f (Icc a b)
hfd : DifferentiableOn ℝ f (Ioo a b)
hfB : ∀ᵐ (t : ℝ), t ∈ Ioo a b → ‖deriv f t‖ ≤ B t
hBi : IntervalIntegrable B volume a b
this✝ :
  ∀ {E : Type u_1} [inst : NormedAddCommGroup E] [inst_1 : NormedSpace ℝ E] {f : ℝ → E},
    ContinuousOn f (Icc a b) →
      DifferentiableOn ℝ f (Ioo a b) →
        (∀ᵐ (t : ℝ), t ∈ Ioo a b → ‖deriv f t‖ ≤ B t) → CompleteSpace E → ‖f b - f a‖ ≤ ∫ (t : ℝ) in a..b, B t
hE : ¬CompleteSpace E
g : ℝ → UniformSpace.Completion E := UniformSpace.Completion.coe' ∘ f
hg : g = UniformSpace.Completion.coe' ∘ f
hgc : ContinuousOn g (Icc a b)
hgd : DifferentiableOn ℝ g (Ioo a b)
t : ℝ
ht : t ∈ Ioo a b
this : HasFDerivAt UniformSpace.Completion.coe' UniformSpace.Completion.toComplL (f t)
hdft : HasDerivAt f (deriv f t) t
⊢ deriv g t = ↑(deriv f t)

Tactic:
hg,

Goal state after:
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : ℝ → E
a b : ℝ
B : ℝ → ℝ
hab : a ≤ b
hfc : ContinuousOn f (Icc a b)
hfd : DifferentiableOn ℝ f (Ioo a b)
hfB : ∀ᵐ (t : ℝ), t ∈ Ioo a b → ‖deriv f t‖ ≤ B t
hBi : IntervalIntegrable B volume a b
this✝ :
  ∀ {E : Type u_1} [inst : NormedAddCommGroup E] [inst_1 : NormedSpace ℝ E] {f : ℝ → E},
    ContinuousOn f (Icc a b) →
      DifferentiableOn ℝ f (Ioo a b) →
        (∀ᵐ (t : ℝ), t ∈ Ioo a b → ‖deriv f t‖ ≤ B t) → CompleteSpace E → ‖f b - f a‖ ≤ ∫ (t : ℝ) in a..b, B t
hE : ¬CompleteSpace E
g : ℝ → UniformSpace.Completion E := UniformSpace.Completion.coe' ∘ f
hg : g = UniformSpace.Completion.coe' ∘ f
hgc : ContinuousOn g (Icc a b)
hgd : DifferentiableOn ℝ g (Ioo a b)
t : ℝ
ht : t ∈ Ioo a b
this : HasFDerivAt UniformSpace.Completion.coe' UniformSpace.Completion.toComplL (f t)
hdft : HasDerivAt f (deriv f t) t
⊢ deriv (UniformSpace.Completion.coe' ∘ f) t = ↑(deriv f t)
Module: Mathlib.MeasureTheory.Integral.CurveIntegral.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace 𝕜 F
a b : E
γ : Path a b
⊢ curveIntegral 0 γ = 0

Tactic:
by simp [curveIntegral]

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

Goal state before:
pp: f : ℝ → ℝ
N : ℕ
a h : ℝ
N_nonzero : 0 < N
⊢ h / 2 * ∑ i ∈ Finset.range N, (f (a + ↑i * h) + f (a + (↑i + 1) * h)) =
    ↑N * (h / ↑N) * ((f a + f (a + ↑N * h)) / 2 + ∑ x ∈ Finset.range (N - 1), f (a + (↑x + 1) * (↑N * (h / ↑N))))

Tactic:
show N * (h / N) = h by field

Goal state after:
f : ℝ → ℝ
N : ℕ
a h : ℝ
N_nonzero : 0 < N
⊢ h / 2 * ∑ i ∈ Finset.range N, (f (a + ↑i * h) + f (a + (↑i + 1) * h)) =
    h * ((f a + f (a + ↑N * h)) / 2 + ∑ x ∈ Finset.range (N - 1), f (a + (↑x + 1) * h))
Module: Mathlib.MeasureTheory.Integral.RieszMarkovKakutani.Basic

Goal state before:
pp: case left
X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : T2Space X
inst✝ : LocallyCompactSpace X
s₀ s₁ t : Set X
s₀_compact : IsCompact s₀
s₁_compact : IsCompact s₁
t_compact : IsCompact t
disj : s₀ᶜ ∪ s₁ᶜ = univ
hst : s₀ ∪ s₁ ⊆ t
so : Fin 2 → Set X := ⋯
hso : so = fun j ↦ if j = 0 then s₀ᶜ else s₁ᶜ
soopen : ∀ (j : Fin 2), IsOpen (so j)
x : X
hx : x ∈ t
h : x ∈ s₀ᶜ ∨ x ∈ s₁ᶜ
⊢ x ∈ s₀ᶜ → ∃ i, x ∈ if i = 0 then s₀ᶜ else s₁ᶜ

Tactic:
intro h0
      use 0
      simp only [Fin.isValue, ↓reduceIte]
      exact h0

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

Goal state before:
pp: f : ℝ → ℝ
ζ a b : ℝ
a_lt_b : a < b
h_df : DifferentiableOn ℝ f (Set.Icc a b)
h_ddf : DifferentiableOn ℝ (_root_.derivWithin f (Set.Icc a b)) (Set.Icc a b)
fpp_bound : ∀ (x : ℝ), |iteratedDerivWithin 2 f (Set.Icc a b) x| ≤ ζ
g : ℝ → ℝ := fun t ↦ trapezoidal_error f 1 a t
dg : ℝ → ℝ := fun t ↦ 1 / 2 * (f a + f t) + (t - a) / 2 * _root_.derivWithin f (Set.Icc a b) t - f t
ddg : ℝ → ℝ := fun t ↦ (t - a) / 2 * iteratedDerivWithin 2 f (Set.Icc a b) t
h_dg : ∀ y ∈ Set.Icc a b, HasDerivWithinAt g (dg y) (Set.Icc a b) y
h_ddg : ∀ y ∈ Set.Icc a b, HasDerivWithinAt dg (ddg y) (Set.Icc a b) y
bound_ddg : ∀ x ∈ Set.Icc a b, |ddg x| ≤ ζ / 2 * (x - a) ^ 1
key :
  ∀ {φ φ' : ℝ → ℝ},
    (∀ x ∈ Set.Icc a b, HasDerivWithinAt φ (φ' x) (Set.Icc a b) x) →
      φ a = 0 →
        ∀ {c : ℝ} {n : ℕ},
          (∀ t ∈ Set.Icc a b, |φ' t| ≤ c * (t - a) ^ n) → ∀ t ∈ Set.Icc a b, |φ t| ≤ c / (↑n + 1) * (t - a) ^ (n + 1)
⊢ |trapezoidal_error f 1 a b| ≤ ζ / 12 * (b - a) ^ 3

Tactic:
exact (key h_dg (trapezoidal_error_eq f 1 a) (key h_ddg (by ring) bound_ddg) b
    ⟨a_lt_b.le, le_rfl⟩).trans_eq (by ring_nf)

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

Goal state before:
pp: X : Type u_1
inst✝² : TopologicalSpace X
Λ : (X →C_c ℝ≥0) →ₗ[ℝ≥0] ℝ≥0
inst✝¹ : T2Space X
inst✝ : LocallyCompactSpace X
K₁ K₂ : Compacts X
disj : Disjoint ↑K₁ ↑K₂
b : ℝ≥0
f : X →C_c ℝ≥0
hf : f ∈ {f | ∀ x ∈ K₁ ⊔ K₂, 1 ≤ f x}
Λf_eq_b : Λ f = b
hsuppf : ∀ x ∈ K₁ ⊔ K₂, x ∈ support ⇑f
hsubsuppf : ↑K₁ ∪ ↑K₂ ⊆ tsupport ⇑f
g₁ g₂ : X →C_c ℝ≥0
hg₁ : EqOn (⇑g₁) 1 K₁.carrier
hg₂ : EqOn (⇑g₂) 1 K₂.carrier
sum_g : EqOn (⇑(g₁ + g₂)) 1 (tsupport f.toFun)
x : X
⊢ ↑(f x) = ↑((g₁ * f + g₂ * f) x)

Tactic:
simp only [CompactlySupportedContinuousMap.coe_add, CompactlySupportedContinuousMap.coe_mul,
      Pi.mul_apply, NNReal.coe_mul,
      Eq.symm (RightDistribClass.right_distrib _ _ _)]

Goal state after:
X : Type u_1
inst✝² : TopologicalSpace X
Λ : (X →C_c ℝ≥0) →ₗ[ℝ≥0] ℝ≥0
inst✝¹ : T2Space X
inst✝ : LocallyCompactSpace X
K₁ K₂ : Compacts X
disj : Disjoint ↑K₁ ↑K₂
b : ℝ≥0
f : X →C_c ℝ≥0
hf : f ∈ {f | ∀ x ∈ K₁ ⊔ K₂, 1 ≤ f x}
Λf_eq_b : Λ f = b
hsuppf : ∀ x ∈ K₁ ⊔ K₂, x ∈ support ⇑f
hsubsuppf : ↑K₁ ∪ ↑K₂ ⊆ tsupport ⇑f
g₁ g₂ : X →C_c ℝ≥0
hg₁ : EqOn (⇑g₁) 1 K₁.carrier
hg₂ : EqOn (⇑g₂) 1 K₂.carrier
sum_g : EqOn (⇑(g₁ + g₂)) 1 (tsupport f.toFun)
x : X
⊢ ↑(f x) = ↑((⇑g₁ + ⇑g₂) x) * ↑(f x)
Module: Mathlib.MeasureTheory.Integral.RieszMarkovKakutani.Real

Goal state before:
pp: case calc_1.e_6
X : Type u_1
inst✝⁴ : TopologicalSpace X
inst✝³ : T2Space X
inst✝² : MeasurableSpace X
inst✝¹ : BorelSpace X
Λ : (X →C_c ℝ) →ₚ[ℝ] ℝ
inst✝ : LocallyCompactSpace X
f : X →C_c ℝ
μ : Measure X := rieszMeasure Λ
K : Set X := tsupport ⇑f
ε : ℝ
hε : 0 < ε
a b : ℝ
hab : a < b ∧ range ⇑f ⊆ Ioo a b
N : ℕ
hN : 0 < N
ε' : ℝ := (b - a) / ↑N
hε' : 0 < ε' ∧ ε' * (2 * μ.real K + |a| + b + ε') ≤ ε
E : Fin N → Set X
hE :
  tsupport ⇑f = ⋃ j, E j ∧
    univ.PairwiseDisjoint E ∧
      (∀ (n : Fin N), ∀ x ∈ E n, a + ε' * ↑↑n < f x ∧ f x ≤ a + ε' * (↑↑n + 1)) ∧ ∀ (n : Fin N), MeasurableSet (E n)
y : Fin N → ℝ := fun n ↦ a + ε' * (↑↑n + 1)
hE' : ∀ (n : Fin N), μ (E n) ≠ ∞
V : Fin N → Opens X
hV : ∀ (n : Fin N), E n ⊆ ↑(V n) ∧ (∀ x ∈ V n, f x < y n + ε') ∧ μ ↑(V n) ≤ μ (E n) + ENNReal.ofReal (ε' / ↑N)
g : Fin N → X →C_c ℝ
hg :
  (∀ (n : Fin N), tsupport ⇑(g n) ⊆ (V n).carrier) ∧
    EqOn (∑ n, ⇑(g n)) 1 (tsupport f.toFun) ∧
      (∀ (n : Fin N) (x : X), (g n) x ∈ Icc 0 1) ∧ ∀ (n : Fin N), HasCompactSupport ⇑(g n)
x : X
⊢ f x = (∑ n, g n • f) x

Tactic:
simp only [coe_sum, smul_eq_mul, coe_mul, Pi.mul_apply,
      ← Finset.sum_mul]

Goal state after:
case calc_1.e_6
X : Type u_1
inst✝⁴ : TopologicalSpace X
inst✝³ : T2Space X
inst✝² : MeasurableSpace X
inst✝¹ : BorelSpace X
Λ : (X →C_c ℝ) →ₚ[ℝ] ℝ
inst✝ : LocallyCompactSpace X
f : X →C_c ℝ
μ : Measure X := rieszMeasure Λ
K : Set X := tsupport ⇑f
ε : ℝ
hε : 0 < ε
a b : ℝ
hab : a < b ∧ range ⇑f ⊆ Ioo a b
N : ℕ
hN : 0 < N
ε' : ℝ := (b - a) / ↑N
hε' : 0 < ε' ∧ ε' * (2 * μ.real K + |a| + b + ε') ≤ ε
E : Fin N → Set X
hE :
  tsupport ⇑f = ⋃ j, E j ∧
    univ.PairwiseDisjoint E ∧
      (∀ (n : Fin N), ∀ x ∈ E n, a + ε' * ↑↑n < f x ∧ f x ≤ a + ε' * (↑↑n + 1)) ∧ ∀ (n : Fin N), MeasurableSet (E n)
y : Fin N → ℝ := fun n ↦ a + ε' * (↑↑n + 1)
hE' : ∀ (n : Fin N), μ (E n) ≠ ∞
V : Fin N → Opens X
hV : ∀ (n : Fin N), E n ⊆ ↑(V n) ∧ (∀ x ∈ V n, f x < y n + ε') ∧ μ ↑(V n) ≤ μ (E n) + ENNReal.ofReal (ε' / ↑N)
g : Fin N → X →C_c ℝ
hg :
  (∀ (n : Fin N), tsupport ⇑(g n) ⊆ (V n).carrier) ∧
    EqOn (∑ n, ⇑(g n)) 1 (tsupport f.toFun) ∧
      (∀ (n : Fin N) (x : X), (g n) x ∈ Icc 0 1) ∧ ∀ (n : Fin N), HasCompactSupport ⇑(g n)
x : X
⊢ f x = (∑ i, ⇑(g i)) x * f x
Module: Mathlib.MeasureTheory.Measure.CharacteristicFunction.Basic

Goal state before:
pp: E : Type u_2
mE : MeasurableSpace E
μ : Measure E
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace ℝ E
t : E
⊢ charFun μ t = ∫ (x : E), ↑(probChar ⟪x, t⟫) ∂μ

Tactic:
simp [charFun_apply, probChar_apply]

Goal state after:
Module: Mathlib.Topology.Separation.CompletelyRegular

Goal state before:
pp: case h.right.right
ι : Type u_1
X : Type u_2
t : ι → TopologicalSpace X
ht : ∀ (i : ι), CompletelyRegularSpace X
this : TopologicalSpace X := ⋯
x : X
I' : Finset ι
V U : ↥I' → Set X
hUV : ∀ (i : ↥I'), U i ⊆ V i
fs : ↥I' → X → ↑I
hfs : ∀ (i : ↥I'), Continuous[t ↑i, _] (fs i)
hxfs : ∀ (i : ↥I'), fs i x = 0
hfsU : ∀ (i : ↥I'), EqOn (fs i) 1 (U i)ᶜ
⊢ EqOn (I'.attach.sup fs) 1 (⋂ i, V i)ᶜ

Tactic:
· simp only [EqOn, Pi.one_apply, show (1 : ↥I) = ⊤ from rfl] at hfsU ⊢
    conv => equals ∀ x i, x ∈ (V i)ᶜ → ∃ b, fs b x = ⊤ => simp [Finset.sup_eq_top_iff]
    intro x i hxi
    specialize hfsU i (by tauto_set)
    exists i

Goal state after:
Module: Mathlib.MeasureTheory.Measure.LevyProkhorovMetric

Goal state before:
pp: Ω : Type u_1
inst✝¹ : MeasurableSpace Ω
inst✝ : PseudoEMetricSpace Ω
μ ν : Measure Ω
⊢ levyProkhorovEDist μ ν ≤ max (μ univ) (ν univ)

Tactic:
refine sInf_le fun B _ ↦ ⟨?_, ?_⟩

Goal state after:
case refine_1
Ω : Type u_1
inst✝¹ : MeasurableSpace Ω
inst✝ : PseudoEMetricSpace Ω
μ ν : Measure Ω
B : Set Ω
x✝ : MeasurableSet B
⊢ μ B ≤ ν (thickening (max (μ univ) (ν univ)).toReal B) + max (μ univ) (ν univ)

case refine_2
Ω : Type u_1
inst✝¹ : MeasurableSpace Ω
inst✝ : PseudoEMetricSpace Ω
μ ν : Measure Ω
B : Set Ω
x✝ : MeasurableSet B
⊢ ν B ≤ μ (thickening (max (μ univ) (ν univ)).toReal B) + max (μ univ) (ν univ)
Module: Mathlib.MeasureTheory.Measure.FiniteMeasurePi

Goal state before:
pp: ι : Type u_1
α : ι → Type u_2
inst✝¹ : Fintype ι
inst✝ : (i : ι) → MeasurableSpace (α i)
μ : (i : ι) → FiniteMeasure (α i)
⊢ (pi μ).mass = ∏ i, (μ i).mass

Tactic:
by
  simp only [mass]
  rw [← pi_univ (univ : Set ι), pi_pi]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.LevyProkhorovMetric

Goal state before:
pp: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : PseudoMetricSpace Ω
inst✝² : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
ε : ℝ
ε_pos : 0 < ε
hμν : levyProkhorovEDist μ ν < ENNReal.ofReal ε
f : Ω →ᵇ ℝ
f_nn : 0 ≤ᵐ[μ] ⇑f
key : (fun t ↦ μ.real {a | t ≤ f a}) ≤ fun t ↦ ν.real (thickening ε {a | t ≤ f a}) + ε
intble₁ : IntegrableOn (fun t ↦ μ.real {a | t ≤ f a}) (Ioc 0 ‖f‖) volume
t : ℝ
⊢ ν univ ≠ ∞

Tactic:
by finiteness

Goal state after: