mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.AlgebraicTopology.SimplicialSet.TopAdj

Goal state before:
pp: n m : SimplexCategory
f : n ⟶ m
⊢ ⇑m.toTopHomeo.symm ∘ stdSimplex.map ⇑(ConcreteCategory.hom f) =
    ⇑(TopCat.Hom.hom (SSet.toTop.map (SSet.stdSimplex.map f))) ∘ ⇑n.toTopHomeo.symm

Tactic:
ext x : 1

Goal state after:
n m : SimplexCategory
f : n ⟶ m
x : ↑(_root_.stdSimplex ℝ ((fun X ↦ Fin (X.len + 1)) n))
⊢ (⇑m.toTopHomeo.symm ∘ stdSimplex.map ⇑(ConcreteCategory.hom f)) x =
    (⇑(TopCat.Hom.hom (SSet.toTop.map (SSet.stdSimplex.map f))) ∘ ⇑n.toTopHomeo.symm) x
Module: Mathlib.Analysis.AbsoluteValue.Equivalence

Goal state before:
pp: case inr
R : Type u_1
S : Type u_2
inst✝⁵ : Field R
inst✝⁴ : Semifield S
inst✝³ : LinearOrder S
v w : AbsoluteValue R S
inst✝² : IsStrictOrderedRing S
inst✝¹ : Archimedean S
inst✝ : ExistsAddOfLE S
hv : v.IsNontrivial
h : ∀ (x : R), v x < 1 → w x < 1
a : R
ha₀ : a ≠ 0
⊢ v a < 1 ↔ w a < 1

Tactic:
refine ⟨h a, fun hw ↦ ?_⟩

Goal state after:
case inr
R : Type u_1
S : Type u_2
inst✝⁵ : Field R
inst✝⁴ : Semifield S
inst✝³ : LinearOrder S
v w : AbsoluteValue R S
inst✝² : IsStrictOrderedRing S
inst✝¹ : Archimedean S
inst✝ : ExistsAddOfLE S
hv : v.IsNontrivial
h : ∀ (x : R), v x < 1 → w x < 1
a : R
ha₀ : a ≠ 0
hw : w a < 1
⊢ v a < 1
Module: Mathlib.Analysis.SpecialFunctions.Complex.Analytic

Goal state before:
pp: n : ℕ
x : ℂ
hx : x ∈ slitPlane
⊢ deriv log =ᶠ[𝓝 x] Inv.inv

Tactic:
filter_upwards [isOpen_slitPlane.mem_nhds hx] with y hy

Goal state after:
n : ℕ
x : ℂ
hx : x ∈ slitPlane
y : ℂ
hy : y ∈ slitPlane
⊢ deriv log y = y⁻¹
Module: Mathlib.Analysis.Analytic.Order

Goal state before:
pp: case neg
𝕜 : Type u_1
E : Type u_2
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : CharZero 𝕜
inst✝ : CompleteSpace E
f : 𝕜 → E
hf : AnalyticAt 𝕜 f 0
n : ℕ
F : 𝕜 → E
hFa : AnalyticAt 𝕜 F 0
hF : ∀ᶠ (z : 𝕜) in 𝓝 0, f z = ∑ i ∈ Finset.range n, (z ^ i / ↑i.factorial) • iteratedDeriv i f 0 + z ^ n • F z
U : Set 𝕜
hU0 : U ∈ 𝓝 0
hU' : ∀ y ∈ U, f y = ∑ i ∈ Finset.range n, (y ^ i / ↑i.factorial) • iteratedDeriv i f 0 + y ^ n • F y
z : 𝕜
hz : z ∉ U
⊢ f z =
    ∑ i ∈ Finset.range n, (z ^ i / ↑i.factorial) • iteratedDeriv i f 0 +
      z ^ n •
        (fun z ↦
            if z ∈ U then F z
            else (z ^ n)⁻¹ • (f z - ∑ i ∈ Finset.range n, (z ^ i / ↑i.factorial) • iteratedDeriv i f 0))
          z

Tactic:
simp only [if_neg hz]

Goal state after:
case neg
𝕜 : Type u_1
E : Type u_2
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : CharZero 𝕜
inst✝ : CompleteSpace E
f : 𝕜 → E
hf : AnalyticAt 𝕜 f 0
n : ℕ
F : 𝕜 → E
hFa : AnalyticAt 𝕜 F 0
hF : ∀ᶠ (z : 𝕜) in 𝓝 0, f z = ∑ i ∈ Finset.range n, (z ^ i / ↑i.factorial) • iteratedDeriv i f 0 + z ^ n • F z
U : Set 𝕜
hU0 : U ∈ 𝓝 0
hU' : ∀ y ∈ U, f y = ∑ i ∈ Finset.range n, (y ^ i / ↑i.factorial) • iteratedDeriv i f 0 + y ^ n • F y
z : 𝕜
hz : z ∉ U
⊢ f z =
    ∑ i ∈ Finset.range n, (z ^ i / ↑i.factorial) • iteratedDeriv i f 0 +
      z ^ n • (z ^ n)⁻¹ • (f z - ∑ i ∈ Finset.range n, (z ^ i / ↑i.factorial) • iteratedDeriv i f 0)
Module: Mathlib.Analysis.Analytic.Order

Goal state before:
pp: case pos
𝕜 : Type u_1
E : Type u_2
inst✝² : NontriviallyNormedField 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
f : 𝕜 → E
g : 𝕜 → 𝕜
z₀ : 𝕜
hf : AnalyticAt 𝕜 f (g z₀)
hg : AnalyticAt 𝕜 g z₀
hg_nc : ¬EventuallyConst g (𝓝 z₀)
hf' : analyticOrderAt f (g z₀) = ⊤
⊢ analyticOrderAt (f ∘ g) z₀ = ⊤ * analyticOrderAt (fun x ↦ g x - g z₀) z₀

Tactic:
analyticOrderAt_eq_top.mpr
      (EventuallyEq.comp_tendsto (analyticOrderAt_eq_top.mp hf') hg.continuousAt),

Goal state after:
case pos
𝕜 : Type u_1
E : Type u_2
inst✝² : NontriviallyNormedField 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
f : 𝕜 → E
g : 𝕜 → 𝕜
z₀ : 𝕜
hf : AnalyticAt 𝕜 f (g z₀)
hg : AnalyticAt 𝕜 g z₀
hg_nc : ¬EventuallyConst g (𝓝 z₀)
hf' : analyticOrderAt f (g z₀) = ⊤
⊢ ⊤ = ⊤ * analyticOrderAt (fun x ↦ g x - g z₀) z₀
Module: Mathlib.Analysis.Meromorphic.Basic

Goal state before:
pp: case inr
𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_3
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
f : 𝕜 → E
z₀ : 𝕜
n : ℕ
h : AnalyticAt 𝕜 (fun z ↦ (z - z₀) ^ n • f z) z₀
h₂ : ∀ᶠ (z : 𝕜) in 𝓝[≠] z₀, (z - z₀) ^ n • f z ≠ 0
⊢ (∀ᶠ (z : 𝕜) in 𝓝[≠] z₀, f z = 0) ∨ ∀ᶠ (z : 𝕜) in 𝓝[≠] z₀, f z ≠ 0

Tactic:
· right
    filter_upwards [h₂, self_mem_nhdsWithin] with y h₁y h₂y
    exact (smul_ne_zero_iff.1 h₁y).2

Goal state after:
Module: Mathlib.RingTheory.Binomial

Goal state before:
pp: R : Type u_2
inst✝³ : NonAssocSemiring R
inst✝² : Pow R ℕ
inst✝¹ : NatPowAssoc R
inst✝ : BinomialRing R
k : ℕ
⊢ (ascPochhammer ℕ (k + 1)).smeval 0 = (k + 1).factorial • 0

Tactic:
smul_zero,

Goal state after:
R : Type u_2
inst✝³ : NonAssocSemiring R
inst✝² : Pow R ℕ
inst✝¹ : NatPowAssoc R
inst✝ : BinomialRing R
k : ℕ
⊢ (ascPochhammer ℕ (k + 1)).smeval 0 = 0
Module: Mathlib.Analysis.Meromorphic.Basic

Goal state before:
pp: 𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_3
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
g : 𝕜 → 𝕜
x : 𝕜
f : 𝕜 → E
hg : AnalyticAt 𝕜 g x
hg' : g x ≠ 0
hfg : MeromorphicAt (g • f) x
z : 𝕜
hz : g z ≠ 0
⊢ (g⁻¹ • g • f) z = f z

Tactic:
simp [inv_smul_smul₀ hz]

Goal state after:
Module: Mathlib.RingTheory.Binomial

Goal state before:
pp: R : Type u_1
inst✝³ : NonAssocRing R
inst✝² : Pow R ℕ
inst✝¹ : BinomialRing R
inst✝ : NatPowAssoc R
n : ℕ
⊢ (n + 1).factorial • multichoose (-↑n) (n + 1) = (n + 1).factorial • 0

Tactic:
smul_zero,

Goal state after:
R : Type u_1
inst✝³ : NonAssocRing R
inst✝² : Pow R ℕ
inst✝¹ : BinomialRing R
inst✝ : NatPowAssoc R
n : ℕ
⊢ (n + 1).factorial • multichoose (-↑n) (n + 1) = 0
Module: Mathlib.Analysis.Asymptotics.LinearGrowth

Goal state before:
pp: ⊢ linearGrowthSup ⊤ = ⊤

Tactic:
apply top_le_iff.1

Goal state after:
⊢ ⊤ ≤ linearGrowthSup ⊤
Module: Mathlib.Analysis.Asymptotics.SuperpolynomialDecay

Goal state before:
pp: α : Type u_1
β : Type u_2
l : Filter α
k f g : α → β
inst✝² : TopologicalSpace β
inst✝¹ : CommSemiring β
inst✝ : ContinuousAdd β
hf : SuperpolynomialDecay l k f
hg : SuperpolynomialDecay l k g
z : ℕ
⊢ Tendsto (fun a ↦ k a ^ z * (f + g) a) l (𝓝 0)

Tactic:
by
  simpa only [mul_add, add_zero, Pi.add_apply] using (hf z).add (hg z)

Goal state after:
Module: Mathlib.Analysis.Asymptotics.SuperpolynomialDecay

Goal state before:
pp: α : Type u_1
β : Type u_2
l : Filter α
k f : α → β
inst✝⁴ : TopologicalSpace β
inst✝³ : Field β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
inst✝ : OrderTopology β
hk : Tendsto k l atTop
h : ∀ (z : ℕ), IsBoundedUnder (fun x1 x2 ↦ x1 ≤ x2) l fun a ↦ |k a ^ z * f a|
z : ℕ
m : β
hm : ∀ᶠ (x : β) in Filter.map (fun a ↦ |k a ^ (z + 1) * f a|) l, (fun x1 x2 ↦ x1 ≤ x2) x m
h1 : Tendsto (fun x ↦ 0) l (𝓝 0)
h2 : Tendsto (fun a ↦ |(k a)⁻¹| * m) l (𝓝 0)
x : α
hk0 : k x ≠ 0
hx : (fun x1 x2 ↦ x1 ≤ x2) |k x ^ (z + 1) * f x| m
⊢ |k x ^ z * f x| ≤ |(k x)⁻¹| * m

Tactic:
refine Eq.trans_le ?_ (mul_le_mul_of_nonneg_left hx <| abs_nonneg (k x)⁻¹)

Goal state after:
α : Type u_1
β : Type u_2
l : Filter α
k f : α → β
inst✝⁴ : TopologicalSpace β
inst✝³ : Field β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
inst✝ : OrderTopology β
hk : Tendsto k l atTop
h : ∀ (z : ℕ), IsBoundedUnder (fun x1 x2 ↦ x1 ≤ x2) l fun a ↦ |k a ^ z * f a|
z : ℕ
m : β
hm : ∀ᶠ (x : β) in Filter.map (fun a ↦ |k a ^ (z + 1) * f a|) l, (fun x1 x2 ↦ x1 ≤ x2) x m
h1 : Tendsto (fun x ↦ 0) l (𝓝 0)
h2 : Tendsto (fun a ↦ |(k a)⁻¹| * m) l (𝓝 0)
x : α
hk0 : k x ≠ 0
hx : (fun x1 x2 ↦ x1 ≤ x2) |k x ^ (z + 1) * f x| m
⊢ |k x ^ z * f x| = |(k x)⁻¹| * |k x ^ (z + 1) * f x|
Module: Mathlib.Analysis.Asymptotics.ExpGrowth

Goal state before:
pp: ⊢ expGrowthInf 0 = ⊥

Tactic:
apply le_bot_iff.1
  rw [← expGrowthSup_zero]
  exact expGrowthInf_le_expGrowthSup

Goal state after:
Module: Mathlib.Analysis.Asymptotics.ExpGrowth

Goal state before:
pp: ⊢ expGrowthSup ⊤ = ⊤

Tactic:
apply top_le_iff.1

Goal state after:
⊢ ⊤ ≤ expGrowthSup ⊤
Module: Mathlib.Analysis.Asymptotics.LinearGrowth

Goal state before:
pp: u : ℕ → EReal
v : ℕ → ℕ
h : Monotone u
hv : Tendsto v atTop atTop
h' : ∃ x, ¬u x = ⊥ x
⊢ 0 ≤ linearGrowthInf (u ∘ v)

Tactic:
obtain ⟨m, hum⟩ := h'

Goal state after:
u : ℕ → EReal
v : ℕ → ℕ
h : Monotone u
hv : Tendsto v atTop atTop
m : ℕ
hum : ¬u m = ⊥ m
⊢ 0 ≤ linearGrowthInf (u ∘ v)
Module: Mathlib.MeasureTheory.Measure.Decomposition.Hahn

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
d : Set α → ℝ := fun s ↦ ↑(μ s).toNNReal - ↑(ν s).toNNReal
⊢ ∃ s,
    MeasurableSet s ∧
      (∀ (t : Set α), MeasurableSet t → t ⊆ s → ν t ≤ μ t) ∧ ∀ (t : Set α), MeasurableSet t → t ⊆ sᶜ → μ t ≤ ν t

Tactic:
let c : Set ℝ := d '' { s | MeasurableSet s }

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
d : Set α → ℝ := fun s ↦ ↑(μ s).toNNReal - ↑(ν s).toNNReal
c : Set ℝ := d '' {s | MeasurableSet s}
⊢ ∃ s,
    MeasurableSet s ∧
      (∀ (t : Set α), MeasurableSet t → t ⊆ s → ν t ≤ μ t) ∧ ∀ (t : Set α), MeasurableSet t → t ⊆ sᶜ → μ t ≤ ν t
Module: Mathlib.MeasureTheory.Measure.Decomposition.Hahn

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
d : Set α → ℝ := fun s ↦ ↑(μ s).toNNReal - ↑(ν s).toNNReal
c : Set ℝ := d '' {s | MeasurableSet s}
γ : ℝ := sSup c
hμ : ∀ (s : Set α), μ s ≠ ∞
hν : ∀ (s : Set α), ν s ≠ ∞
to_nnreal_μ : ∀ (s : Set α), ↑(μ s).toNNReal = μ s
to_nnreal_ν : ∀ (s : Set α), ↑(ν s).toNNReal = ν s
d_split : ∀ (s t : Set α), MeasurableSet t → d s = d (s \ t) + d (s ∩ t)
d_Union : ∀ (s : ℕ → Set α), Monotone s → Tendsto (fun n ↦ d (s n)) atTop (𝓝 (d (⋃ n, s n)))
d_Inter :
  ∀ (s : ℕ → Set α),
    (∀ (n : ℕ), MeasurableSet (s n)) →
      (∀ (n m : ℕ), n ≤ m → s m ⊆ s n) → Tendsto (fun n ↦ d (s n)) atTop (𝓝 (d (⋂ n, s n)))
bdd_c : BddAbove c
c_nonempty : c.Nonempty
d_le_γ : ∀ (s : Set α), MeasurableSet s → d s ≤ γ
this : ∀ (n : ℕ), ∃ s, MeasurableSet s ∧ γ - (1 / 2) ^ n < d s
e : ℕ → Set α
he : ∀ (x : ℕ), MeasurableSet (e x) ∧ γ - (1 / 2) ^ x < d (e x)
⊢ ∃ s,
    MeasurableSet s ∧
      (∀ (t : Set α), MeasurableSet t → t ⊆ s → ν t ≤ μ t) ∧ ∀ (t : Set α), MeasurableSet t → t ⊆ sᶜ → μ t ≤ ν t

Tactic:
have he₁ : ∀ n, MeasurableSet (e n) := fun n => (he n).1

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
d : Set α → ℝ := fun s ↦ ↑(μ s).toNNReal - ↑(ν s).toNNReal
c : Set ℝ := d '' {s | MeasurableSet s}
γ : ℝ := sSup c
hμ : ∀ (s : Set α), μ s ≠ ∞
hν : ∀ (s : Set α), ν s ≠ ∞
to_nnreal_μ : ∀ (s : Set α), ↑(μ s).toNNReal = μ s
to_nnreal_ν : ∀ (s : Set α), ↑(ν s).toNNReal = ν s
d_split : ∀ (s t : Set α), MeasurableSet t → d s = d (s \ t) + d (s ∩ t)
d_Union : ∀ (s : ℕ → Set α), Monotone s → Tendsto (fun n ↦ d (s n)) atTop (𝓝 (d (⋃ n, s n)))
d_Inter :
  ∀ (s : ℕ → Set α),
    (∀ (n : ℕ), MeasurableSet (s n)) →
      (∀ (n m : ℕ), n ≤ m → s m ⊆ s n) → Tendsto (fun n ↦ d (s n)) atTop (𝓝 (d (⋂ n, s n)))
bdd_c : BddAbove c
c_nonempty : c.Nonempty
d_le_γ : ∀ (s : Set α), MeasurableSet s → d s ≤ γ
this : ∀ (n : ℕ), ∃ s, MeasurableSet s ∧ γ - (1 / 2) ^ n < d s
e : ℕ → Set α
he : ∀ (x : ℕ), MeasurableSet (e x) ∧ γ - (1 / 2) ^ x < d (e x)
he₁ : ∀ (n : ℕ), MeasurableSet (e n)
⊢ ∃ s,
    MeasurableSet s ∧
      (∀ (t : Set α), MeasurableSet t → t ⊆ s → ν t ≤ μ t) ∧ ∀ (t : Set α), MeasurableSet t → t ⊆ sᶜ → μ t ≤ ν t
Module: Mathlib.MeasureTheory.Integral.Average

Goal state before:
pp: α : Type u_1
E : Type u_2
m0 : MeasurableSpace α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : α → E
⊢ ∫ (x : α), f x ∂(0 univ)⁻¹ • 0 = 0

Tactic:
smul_zero,

Goal state after:
α : Type u_1
E : Type u_2
m0 : MeasurableSpace α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : α → E
⊢ ∫ (x : α), f x ∂0 = 0
Module: Mathlib.MeasureTheory.Integral.Average

Goal state before:
pp: α : Type u_1
E : Type u_2
m0 : MeasurableSpace α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
μ : Measure α
f : α → E
s t : Set α
hd : AEDisjoint μ s t
ht : NullMeasurableSet t μ
hs₀ : μ s ≠ 0
ht₀ : μ t ≠ 0
hsμ : μ s ≠ ∞
htμ : μ t ≠ ∞
hfs : IntegrableOn f s μ
hft : IntegrableOn f t μ
⊢ ⨍ (x : α) in s ∪ t, f x ∂μ ∈ openSegment ℝ (⨍ (x : α) in s, f x ∂μ) (⨍ (x : α) in t, f x ∂μ)

Tactic:
replace hs₀ : 0 < μ.real s := ENNReal.toReal_pos hs₀ hsμ
  replace ht₀ : 0 < μ.real t := ENNReal.toReal_pos ht₀ htμ
  exact mem_openSegment_iff_div.mpr
    ⟨μ.real s, μ.real t, hs₀, ht₀, (average_union hd ht hsμ htμ hfs hft).symm⟩

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

Goal state before:
pp: case inr
α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
s : Set α
f : α → ℝ≥0∞
hμ : μ s ≠ 0
hs : NullMeasurableSet s μ
hμ₁ : μ s ≠ ∞
g : α → ℝ≥0∞
hint : ∫⁻ (a : α) in s, g a ∂μ ≠ ∞
hg : Measurable g
hgf : g ≤ f
hfg : ∫⁻ (a : α) in s, f a ∂μ = ∫⁻ (a : α) in s, g a ∂μ
hfg' : ⨍⁻ (a : α) in s, f a ∂μ = ⨍⁻ (a : α) in s, g a ∂μ
this : 0 < (μ.restrict s) ({a | ⨍ (a : α) in s, (g a).toReal ∂μ ≤ (g a).toReal} \ {x | g x = ∞})
x : α
hfx : ⨍ (a : α) in s, (g a).toReal ∂μ ≤ (g x).toReal
hx : x ∉ {x | g x = ∞}
⊢ (μ.restrict s) {a | g a = ∞} = 0

Tactic:
exact measure_eq_top_of_lintegral_ne_top hg.aemeasurable hint

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝ : μ.HaveLebesgueDecomposition ν
⊢ μ.rnDeriv ν =ᵐ[ν] 0 ↔ ν.withDensity (μ.rnDeriv ν) = 0

Tactic:
withDensity_eq_zero_iff (measurable_rnDeriv _ _).aemeasurable

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝ : μ.HaveLebesgueDecomposition ν
⊢ μ.rnDeriv ν =ᵐ[ν] 0 ↔ μ.rnDeriv ν =ᵐ[ν] 0
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: case neg.hnc
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
r : ℝ≥0
hr : ¬r = 0
hl : ¬μ.HaveLebesgueDecomposition ν
hl' : (r • μ).HaveLebesgueDecomposition ν
⊢ μ.HaveLebesgueDecomposition ν

Tactic:
← inv_smul_smul₀ hr μ

Goal state after:
case neg.hnc
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
r : ℝ≥0
hr : ¬r = 0
hl : ¬μ.HaveLebesgueDecomposition ν
hl' : (r • μ).HaveLebesgueDecomposition ν
⊢ (r⁻¹ • r • μ).HaveLebesgueDecomposition ν
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
r : ℝ≥0
⊢ (r • μ).singularPart ν = r • μ.singularPart ν

Tactic:
by
  by_cases hr : r = 0
  · rw [hr, zero_smul, zero_smul, singularPart_zero]
  by_cases hl : HaveLebesgueDecomposition μ ν
  · refine (eq_singularPart ((measurable_rnDeriv μ ν).const_smul (r : ℝ≥0∞))
          (MutuallySingular.smul r (mutuallySingular_singularPart _ _)) ?_).symm
    rw [withDensity_smul _ (measurable_rnDeriv _ _), ← smul_add,
      ← haveLebesgueDecomposition_add μ ν, ENNReal.smul_def]
  · rw [singularPart, singularPart, dif_neg hl, dif_neg, smul_zero]
    refine fun hl' ↦ hl ?_
    rw [← inv_smul_smul₀ hr μ]
    infer_instance

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : μ.HaveLebesgueDecomposition ν
inst✝ : SigmaFinite ν
s : Set α
hs : MeasurableSet s
⊢ (μ.restrict s).rnDeriv ν =ᵐ[ν] s.indicator (μ.rnDeriv ν)

Tactic:
refine (eq_rnDeriv (s := (μ.restrict s).singularPart ν)
    ((measurable_rnDeriv _ _).indicator hs) (mutuallySingular_singularPart _ _) ?_).symm
  rw [singularPart_restrict _ _ hs, withDensity_indicator hs, ← restrict_withDensity hs,
    ← Measure.restrict_add, ← μ.haveLebesgueDecomposition_add ν]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
ν₁ ν₂ μ : Measure α
inst✝⁴ : IsFiniteMeasure ν₁
inst✝³ : IsFiniteMeasure ν₂
inst✝² : ν₁.HaveLebesgueDecomposition μ
inst✝¹ : ν₂.HaveLebesgueDecomposition μ
inst✝ : (ν₁ + ν₂).HaveLebesgueDecomposition μ
⊢ (ν₁ + ν₂).singularPart μ + μ.withDensity ((ν₁ + ν₂).rnDeriv μ) =
    (ν₁ + ν₂).singularPart μ + μ.withDensity (ν₁.rnDeriv μ + ν₂.rnDeriv μ)

Tactic:
rw [← (ν₁ + ν₂).haveLebesgueDecomposition_add μ, singularPart_add,
      withDensity_add_left (measurable_rnDeriv _ _), add_assoc,
      add_comm (ν₂.singularPart μ), add_assoc, add_comm _ (ν₂.singularPart μ),
      ← ν₂.haveLebesgueDecomposition_add μ, ← add_assoc, ← ν₁.haveLebesgueDecomposition_add μ]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
h : ¬μ ⟂ₘ ν
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → ((1 / (↑n + 1)) • ν) (t ∩ f n) ≤ μ (t ∩ f n)
hf₃ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ (f n)ᶜ) ≤ ((1 / (↑n + 1)) • ν) (t ∩ (f n)ᶜ)
A : Set α := ⋂ n, (f n)ᶜ
hAmeas : MeasurableSet A
hA₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ A) ≤ ((1 / (↑n + 1)) • ν) (t ∩ A)
hA₃ : ∀ (n : ℕ), μ A ≤ ↑(1 / (↑n + 1)) * ν A
⊢ ∃ ε, 0 < ε ∧ ∃ E, MeasurableSet E ∧ 0 < ν E ∧ ∀ (A : Set α), MeasurableSet A → ↑ε * ν (A ∩ E) ≤ μ (A ∩ E)

Tactic:
have hμ : μ A = 0 := by
    lift μ A to ℝ≥0 using measure_ne_top _ _ with μA
    lift ν A to ℝ≥0 using measure_ne_top _ _ with νA
    rw [ENNReal.coe_eq_zero]
    by_cases! hb : 0 < νA
    · suffices ∀ b, 0 < b → μA ≤ b by
        by_contra h
        have h' := this (μA / 2) (half_pos (zero_lt_iff.2 h))
        rw [← @Classical.not_not (μA ≤ μA / 2)] at h'
        exact h' (not_le.2 (NNReal.half_lt_self h))
      intro c hc
      have : ∃ n : ℕ, 1 / (n + 1 : ℝ) < c * (νA : ℝ)⁻¹ := by
        refine exists_nat_one_div_lt ?_
        positivity
      rcases this with ⟨n, hn⟩
      have hb₁ : (0 : ℝ) < (νA : ℝ)⁻¹ := by rw [_root_.inv_pos]; exact hb
      have h' : 1 / (↑n + 1) * νA < c := by
        rw [← NNReal.coe_lt_coe, ← mul_lt_mul_iff_left₀ hb₁, NNReal.coe_mul, mul_assoc, ←
          NNReal.coe_inv, ← NNReal.coe_mul, mul_inv_cancel₀, ← NNReal.coe_mul, mul_one,
          NNReal.coe_inv]
        · exact hn
        · exact hb.ne'
      refine le_trans ?_ h'.le
      rw [← ENNReal.coe_le_coe, ENNReal.coe_mul]
      exact hA₃ n
    · rw [le_zero_iff] at hb
      simpa [hb] using hA₃ 0

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
h : ¬μ ⟂ₘ ν
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → ((1 / (↑n + 1)) • ν) (t ∩ f n) ≤ μ (t ∩ f n)
hf₃ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ (f n)ᶜ) ≤ ((1 / (↑n + 1)) • ν) (t ∩ (f n)ᶜ)
A : Set α := ⋂ n, (f n)ᶜ
hAmeas : MeasurableSet A
hA₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ A) ≤ ((1 / (↑n + 1)) • ν) (t ∩ A)
hA₃ : ∀ (n : ℕ), μ A ≤ ↑(1 / (↑n + 1)) * ν A
hμ : μ A = 0
⊢ ∃ ε, 0 < ε ∧ ∃ E, MeasurableSet E ∧ 0 < ν E ∧ ∀ (A : Set α), MeasurableSet A → ↑ε * ν (A ∩ E) ≤ μ (A ∩ E)
Module: Mathlib.Topology.EMetricSpace.BoundedVariation

Goal state before:
pp: α : Type u_1
inst✝¹ : LinearOrder α
E : Type u_2
inst✝ : PseudoEMetricSpace E
f : α → E
s : Set α
u : ℕ → α
u_mono : Monotone u
u_mem : ∀ (i : ℕ), u i ∈ s
⊢ StrictMonoOn u (Iic 0)

Tactic:
grind [StrictMonoOn]

Goal state after:
Module: Mathlib.Topology.EMetricSpace.BoundedVariation

Goal state before:
pp: α : Type u_1
inst✝¹ : LinearOrder α
E : Type u_2
inst✝ : PseudoEMetricSpace E
f : α → E
s : Set α
u : ℕ → α
u_mono : Monotone u
u_mem : ∀ (i : ℕ), u i ∈ s
n m : ℕ
v : ℕ → α
v_mono : StrictMonoOn v (Iic m)
v_mem : ∀ i ∈ Iic m, v i ∈ s
hv : ↑⟨m, ⟨v, ⋯⟩⟩.snd ⟨m, ⟨v, ⋯⟩⟩.fst = u n
h'v :
  ∑ x ∈ Finset.range n, edist (f (u (x + 1))) (f (u x)) =
    ∑ i ∈ Finset.range ⟨m, ⟨v, ⋯⟩⟩.fst, edist (f (↑⟨m, ⟨v, ⋯⟩⟩.snd (i + 1))) (f (↑⟨m, ⟨v, ⋯⟩⟩.snd i))
hn : u n < u (n + 1)
⊢ StrictMonoOn (fun i ↦ if i ≤ m then v i else u (n + 1)) (Iic (m + 1)) ∧
    ∀ i ≤ m + 1, (fun i ↦ if i ≤ m then v i else u (n + 1)) i ∈ s

Tactic:
grind [StrictMonoOn]

Goal state after:
Module: Mathlib.Topology.EMetricSpace.VariationOnFromTo

Goal state before:
pp: α : Type u_1
inst✝ : LinearOrder α
f : α → ℝ
s : Set α
hf : LocallyBoundedVariationOn f s
a b c : α
as : a ∈ s
bs : b ∈ s
cs : c ∈ s
bc : b ≤ c
⊢ edist (f b) (f c) ≤ eVariationOn f (s ∩ Icc b c)

Tactic:
apply eVariationOn.edist_le f

Goal state after:
case hx
α : Type u_1
inst✝ : LinearOrder α
f : α → ℝ
s : Set α
hf : LocallyBoundedVariationOn f s
a b c : α
as : a ∈ s
bs : b ∈ s
cs : c ∈ s
bc : b ≤ c
⊢ b ∈ s ∩ Icc b c

case hy
α : Type u_1
inst✝ : LinearOrder α
f : α → ℝ
s : Set α
hf : LocallyBoundedVariationOn f s
a b c : α
as : a ∈ s
bs : b ∈ s
cs : c ∈ s
bc : b ≤ c
⊢ c ∈ s ∩ Icc b c
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
ν₁ ν₂ μ : Measure α
inst✝² : SigmaFinite ν₁
inst✝¹ : SigmaFinite ν₂
inst✝ : SigmaFinite μ
⊢ (ν₁ + ν₂).singularPart μ + μ.withDensity ((ν₁ + ν₂).rnDeriv μ) =
    (ν₁ + ν₂).singularPart μ + μ.withDensity (ν₁.rnDeriv μ + ν₂.rnDeriv μ)

Tactic:
rw [← (ν₁ + ν₂).haveLebesgueDecomposition_add μ, singularPart_add,
      withDensity_add_left (measurable_rnDeriv _ _), add_assoc,
      add_comm (ν₂.singularPart μ), add_assoc, add_comm _ (ν₂.singularPart μ),
      ← ν₂.haveLebesgueDecomposition_add μ, ← add_assoc, ← ν₁.haveLebesgueDecomposition_add μ]

Goal state after:
Module: Mathlib.Topology.EMetricSpace.BoundedVariation

Goal state before:
pp: case e'_3.a.inl
α : Type u_1
inst✝² : LinearOrder α
E : Type u_2
inst✝¹ : PseudoEMetricSpace E
β : Type u_3
inst✝ : LinearOrder β
f : α → E
t : Set β
φ : β → α
hφ : MonotoneOn φ t
x y : β
hx : x ∈ t
hy : y ∈ t
h : x ≤ y
u : β
us : u ∈ t
vφx : φ x ≤ φ u
vφy : φ u ≤ φ y
xu : x ≤ u
⊢ φ u ∈ φ '' (t ∩ Icc x y)

Tactic:
rcases le_total u y with (uy | yu)

Goal state after:
case e'_3.a.inl.inl
α : Type u_1
inst✝² : LinearOrder α
E : Type u_2
inst✝¹ : PseudoEMetricSpace E
β : Type u_3
inst✝ : LinearOrder β
f : α → E
t : Set β
φ : β → α
hφ : MonotoneOn φ t
x y : β
hx : x ∈ t
hy : y ∈ t
h : x ≤ y
u : β
us : u ∈ t
vφx : φ x ≤ φ u
vφy : φ u ≤ φ y
xu : x ≤ u
uy : u ≤ y
⊢ φ u ∈ φ '' (t ∩ Icc x y)

case e'_3.a.inl.inr
α : Type u_1
inst✝² : LinearOrder α
E : Type u_2
inst✝¹ : PseudoEMetricSpace E
β : Type u_3
inst✝ : LinearOrder β
f : α → E
t : Set β
φ : β → α
hφ : MonotoneOn φ t
x y : β
hx : x ∈ t
hy : y ∈ t
h : x ≤ y
u : β
us : u ∈ t
vφx : φ x ≤ φ u
vφy : φ u ≤ φ y
xu : x ≤ u
yu : y ≤ u
⊢ φ u ∈ φ '' (t ∩ Icc x y)
Module: Mathlib.Topology.EMetricSpace.BoundedVariation

Goal state before:
pp: α : Type u_1
inst✝³ : LinearOrder α
E : Type u_2
inst✝² : PseudoEMetricSpace E
inst✝¹ : TopologicalSpace α
inst✝ : OrderTopology α
f : α → E
s : Set α
a : α
l : E
h : (𝓝[s ∩ Iio a] a).NeBot
ha : a ∈ s
h'f : Tendsto f (𝓝[s ∩ Iio a] a) (𝓝 l)
n : ℕ
u : ℕ → α
u_mono : StrictMonoOn u (Iic n)
u_mem : ∀ i ∈ Iic n, u i ∈ s ∩ Iic a
this : u n ≤ a
hn : u n < a
⊢ ∀ i ≤ n, u i ∈ s ∩ Iio a

Tactic:
grind [StrictMonoOn]

Goal state after:
Module: Mathlib.Topology.EMetricSpace.BoundedVariation

Goal state before:
pp: α : Type u_1
inst✝³ : LinearOrder α
E : Type u_2
inst✝² : PseudoEMetricSpace E
inst✝¹ : TopologicalSpace α
inst✝ : OrderTopology α
f : α → E
s : Set α
a : α
l : E
h : (𝓝[s ∩ Iio a] a).NeBot
ha : a ∈ s
h'f : Tendsto f (𝓝[s ∩ Iio a] a) (𝓝 l)
u : ℕ → α
n : ℕ
u_mono : StrictMonoOn u (Iic (n + 1))
u_mem : ∀ i ∈ Iic (n + 1), u i ∈ s ∩ Iic a
this✝ : u (n + 1) ≤ a
hn : u (n + 1) = a
this :
  Tendsto (fun y ↦ eVariationOn f (s ∩ Iio a) + edist (f a) (f y)) (𝓝[s ∩ Iio a] a)
    (𝓝 (eVariationOn f (s ∩ Iio a) + edist (f a) l))
⊢ u n < a

Tactic:
grind [StrictMonoOn]

Goal state after:
Module: Mathlib.Topology.EMetricSpace.BoundedVariation

Goal state before:
pp: α : Type u_1
inst✝³ : LinearOrder α
E : Type u_2
inst✝² : PseudoEMetricSpace E
inst✝¹ : TopologicalSpace α
inst✝ : OrderTopology α
f : α → E
s : Set α
a : α
l : E
h : (𝓝[s ∩ Iio a] a).NeBot
ha : a ∈ s
h'f : Tendsto f (𝓝[s ∩ Iio a] a) (𝓝 l)
b : α
hb : b ∈ s ∩ Iio a
⊢ StrictMonoOn (fun i ↦ b) (Iic 0) ∧ ∀ i ∈ Iic 0, (fun i ↦ b) i ∈ s ∩ Iio a

Tactic:
grind [StrictMonoOn]

Goal state after: