mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Topology.Instances.Real.Lemmas

Goal state before:
pp: f : ℕ → ℝ
k : ℕ
x : ℝ
h_tto : Tendsto f atTop (𝓝 x)
h_ant : AntitoneOn f (Ici k)
h_bdd : BddBelow (f '' Ici k)
⊢ IsGLB (f '' Ici k) x

Tactic:
tendsto_nhds_unique h_tto
    (Real.tendsto_atTop_csInf_of_antitoneOn_bddBelow_nat_Ici h_ant h_bdd)

Goal state after:
f : ℕ → ℝ
k : ℕ
x : ℝ
h_tto : Tendsto f atTop (𝓝 x)
h_ant : AntitoneOn f (Ici k)
h_bdd : BddBelow (f '' Ici k)
⊢ IsGLB (f '' Ici k) (sInf (f '' Ici k))
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Metrizable

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝⁶ : MeasurableSpace α
inst✝⁵ : TopologicalSpace β
inst✝⁴ : PseudoMetrizableSpace β
inst✝³ : MeasurableSpace β
inst✝² : BorelSpace β
ι : Type u_3
inst✝¹ : Nonempty ι
μ : Measure α
f : ι → α → β
L : Filter ι
inst✝ : L.IsCountablyGenerated
hf : ∀ (n : ι), AEMeasurable (f n) μ
h_ae_tendsto : ∀ᵐ (x : α) ∂μ, ∃ l, Tendsto (fun n ↦ f n x) L (𝓝 l)
inhabited_h : Inhabited ι
hL : L.NeBot
f_lim : α → β := fun x ↦ if h : ∃ l, Tendsto (fun n ↦ f n x) L (𝓝 l) then h.choose else ⋯.some
⊢ ∀ᵐ (x : α) ∂μ, Tendsto (fun n ↦ f n x) L (𝓝 (f_lim x))

Tactic:
filter_upwards [h_ae_tendsto] with x hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝⁶ : MeasurableSpace α
inst✝⁵ : TopologicalSpace β
inst✝⁴ : PseudoMetrizableSpace β
inst✝³ : MeasurableSpace β
inst✝² : BorelSpace β
ι : Type u_3
inst✝¹ : Nonempty ι
μ : Measure α
f : ι → α → β
L : Filter ι
inst✝ : L.IsCountablyGenerated
hf : ∀ (n : ι), AEMeasurable (f n) μ
h_ae_tendsto : ∀ᵐ (x : α) ∂μ, ∃ l, Tendsto (fun n ↦ f n x) L (𝓝 l)
inhabited_h : Inhabited ι
hL : L.NeBot
f_lim : α → β := fun x ↦ if h : ∃ l, Tendsto (fun n ↦ f n x) L (𝓝 l) then h.choose else ⋯.some
x : α
hx : ∃ l, Tendsto (fun n ↦ f n x) L (𝓝 l)
⊢ Tendsto (fun n ↦ f n x) L (𝓝 (f_lim x))
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Real

Goal state before:
pp: μ : Measure ℝ
inst✝ : IsFiniteMeasureOnCompacts μ
b : ℝ
⊢ Tendsto (fun δ ↦ μ (Icc (b - δ) (b + δ))) (𝓝[≥] 0) (𝓝 (μ {b}))

Tactic:
simp only [← nhdsGT_sup_nhdsWithin_singleton, nhdsWithin_singleton, tendsto_sup,
    tendsto_measure_Icc_nhdsWithin_right' μ b, true_and, tendsto_pure_left]
  intro s hs
  simpa using mem_of_mem_nhds hs

Goal state after:
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ μ s = μ (s ∩ (f ⁻¹' {0} ∪ f ⁻¹' Ioi 0))

Tactic:
← preimage_union,

Goal state after:
α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ μ s = μ (s ∩ f ⁻¹' ({0} ∪ Ioi 0))
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ μ s = μ (s ∩ f ⁻¹' {0} ∪ s ∩ f ⁻¹' Ioi 0)

pp: case hd
α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ Disjoint (s ∩ f ⁻¹' {0}) (s ∩ f ⁻¹' Ioi 0)

pp: case h
α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ MeasurableSet (s ∩ f ⁻¹' Ioi 0)

Tactic:
· rw [← inter_union_distrib_left, ← preimage_union, singleton_union, Ioi_insert,
        ← _root_.bot_eq_zero, Ici_bot, preimage_univ, inter_univ]

Goal state after:
case hd
α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ Disjoint (s ∩ f ⁻¹' {0}) (s ∩ f ⁻¹' Ioi 0)

case h
α : Type u_5
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : Measurable f
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
⊢ MeasurableSet (s ∩ f ⁻¹' Ioi 0)
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.AEStronglyMeasurable

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace β
m : MeasurableSpace α
f : α → β
m' m₀ : MeasurableSpace α
μ : Measure α
inst✝ : Zero β
hm : m ≤ m₀
s : Set α
hs_m : MeasurableSet s
hs : ∀ (t : Set α), MeasurableSet (s ∩ t) → MeasurableSet (s ∩ t)
hf : AEStronglyMeasurable f μ
hf_zero : f =ᵐ[μ.restrict sᶜ] 0
⊢ s.indicator (AEStronglyMeasurable.mk f hf) =ᵐ[μ] s.indicator f

Tactic:
filter_upwards [hf.ae_eq_mk] with x hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace β
m : MeasurableSpace α
f : α → β
m' m₀ : MeasurableSpace α
μ : Measure α
inst✝ : Zero β
hm : m ≤ m₀
s : Set α
hs_m : MeasurableSet s
hs : ∀ (t : Set α), MeasurableSet (s ∩ t) → MeasurableSet (s ∩ t)
hf : AEStronglyMeasurable f μ
hf_zero : f =ᵐ[μ.restrict sᶜ] 0
x : α
hx : f x = AEStronglyMeasurable.mk f hf x
⊢ s.indicator (AEStronglyMeasurable.mk f hf) x = s.indicator f x
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.AEStronglyMeasurable

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝ : TopologicalSpace β
m₀ : MeasurableSpace α
μ : Measure α
f : α → β
hf : AEStronglyMeasurable f μ
⊢ ∀ᵐ (x : α) ∂μ, f x ∈ range (AEStronglyMeasurable.mk f hf)

Tactic:
filter_upwards [hf.ae_eq_mk] with x hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝ : TopologicalSpace β
m₀ : MeasurableSpace α
μ : Measure α
f : α → β
hf : AEStronglyMeasurable f μ
x : α
hx : f x = AEStronglyMeasurable.mk f hf x
⊢ f x ∈ range (AEStronglyMeasurable.mk f hf)
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (x : α) in s, f x ∂μ ≤ (⨆ x ∈ s, f x) * μ s

Tactic:
by
  calc ∫⁻ x in s, f x ∂μ
  _ ≤ ∫⁻ y in s, ⨆ x ∈ s, f x ∂μ :=
    setLIntegral_mono' hs fun x hx ↦ le_iSup₂ (f := fun x _ ↦ f x) x hx
  _ = (⨆ x ∈ s, f x) * μ s := by simp

Goal state after:
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
f : α → β
inst✝¹ : TopologicalSpace β
inst✝ : Zero β
m : MeasurableSpace α
μ : Measure α
hf_meas : StronglyMeasurable f
t : Set α
ht : MeasurableSet t
hft_zero : ∀ x ∈ tᶜ, f x = 0
htμ this : SigmaFinite (μ.restrict t)
S : ℕ → Set α := spanningSets (μ.restrict t)
hS_meas : ∀ (n : ℕ), MeasurableSet (S n)
f_approx : ℕ → α →ₛ β := hf_meas.approx
⊢ FinStronglyMeasurable f μ

Tactic:
let fs n := SimpleFunc.restrict (f_approx n) (S n ∩ t)

Goal state after:
α : Type u_1
β : Type u_2
f : α → β
inst✝¹ : TopologicalSpace β
inst✝ : Zero β
m : MeasurableSpace α
μ : Measure α
hf_meas : StronglyMeasurable f
t : Set α
ht : MeasurableSet t
hft_zero : ∀ x ∈ tᶜ, f x = 0
htμ this : SigmaFinite (μ.restrict t)
S : ℕ → Set α := spanningSets (μ.restrict t)
hS_meas : ∀ (n : ℕ), MeasurableSet (S n)
f_approx : ℕ → α →ₛ β := hf_meas.approx
fs : ℕ → α →ₛ β := fun n ↦ (f_approx n).restrict (S n ∩ t)
⊢ FinStronglyMeasurable f μ
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
f : α → β
inst✝¹ : TopologicalSpace β
inst✝ : Zero β
m : MeasurableSpace α
μ : Measure α
hf_meas : StronglyMeasurable f
t : Set α
ht : MeasurableSet t
hft_zero : ∀ x ∈ tᶜ, f x = 0
htμ this : SigmaFinite (μ.restrict t)
S : ℕ → Set α := spanningSets (μ.restrict t)
hS_meas : ∀ (n : ℕ), MeasurableSet (S n)
f_approx : ℕ → α →ₛ β := hf_meas.approx
fs : ℕ → α →ₛ β := fun n ↦ (f_approx n).restrict (S n ∩ t)
h_fs_t_compl : ∀ (n : ℕ), ∀ x ∉ t, (fs n) x = 0
x : α
hxt : x ∈ t
h : Tendsto (fun n ↦ (f_approx n) x) atTop (𝓝 (f x))
n : ℕ
hn : ∀ (m : ℕ), n ≤ m → x ∈ S m
⊢ ∃ n, ∀ (m : ℕ), n ≤ m → x ∈ S m ∩ t

Tactic:
exact ⟨n, fun m hnm => Set.mem_inter (hn m hnm) hxt⟩

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: case intro
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), Measurable (f b)
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
val✝ : Encodable β
⊢ ∫⁻ (a : α), ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ (a : α), f b a ∂μ

Tactic:
cases isEmpty_or_nonempty β

Goal state after:
case intro.inl
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), Measurable (f b)
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
val✝ : Encodable β
h✝ : IsEmpty β
⊢ ∫⁻ (a : α), ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ (a : α), f b a ∂μ

case intro.inr
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), Measurable (f b)
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
val✝ : Encodable β
h✝ : Nonempty β
⊢ ∫⁻ (a : α), ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ (a : α), f b a ∂μ
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Markov

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hfg : f ≤ᵐ[μ] g
hf : ∫⁻ (x : α), f x ∂μ ≠ ∞
hg : AEMeasurable g μ
hgf : ∫⁻ (x : α), g x ∂μ ≤ ∫⁻ (x : α), f x ∂μ
this : ∀ (n : ℕ), ∀ᵐ (x : α) ∂μ, g x < f x + (↑n)⁻¹
x : α
hlt : ∀ (i : ℕ), g x < f x + (↑i)⁻¹
hle : f x ≤ g x
⊢ g x ≤ f x

Tactic:
suffices Tendsto (fun n : ℕ => f x + (n : ℝ≥0∞)⁻¹) atTop (𝓝 (f x)) from
    ge_of_tendsto' this fun i => (hlt i).le

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hfg : f ≤ᵐ[μ] g
hf : ∫⁻ (x : α), f x ∂μ ≠ ∞
hg : AEMeasurable g μ
hgf : ∫⁻ (x : α), g x ∂μ ≤ ∫⁻ (x : α), f x ∂μ
this : ∀ (n : ℕ), ∀ᵐ (x : α) ∂μ, g x < f x + (↑n)⁻¹
x : α
hlt : ∀ (i : ℕ), g x < f x + (↑i)⁻¹
hle : f x ≤ g x
⊢ Tendsto (fun n ↦ f x + (↑n)⁻¹) atTop (𝓝 (f x))
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Sub

Goal state before:
pp: case intro
α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : Countable β
f : β → α → ℝ≥0∞
μ : Measure α
hμ : μ ≠ 0
hf : ∀ (b : β), Measurable (f b)
hf_int : ∀ (b : β), ∫⁻ (a : α), f b a ∂μ ≠ ∞
h_directed : Directed (fun x1 x2 ↦ x1 ≥ x2) f
val✝ : Encodable β
⊢ ∫⁻ (a : α), ⨅ b, f b a ∂μ = ⨅ b, ∫⁻ (a : α), f b a ∂μ

Tactic:
cases isEmpty_or_nonempty β

Goal state after:
case intro.inl
α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : Countable β
f : β → α → ℝ≥0∞
μ : Measure α
hμ : μ ≠ 0
hf : ∀ (b : β), Measurable (f b)
hf_int : ∀ (b : β), ∫⁻ (a : α), f b a ∂μ ≠ ∞
h_directed : Directed (fun x1 x2 ↦ x1 ≥ x2) f
val✝ : Encodable β
h✝ : IsEmpty β
⊢ ∫⁻ (a : α), ⨅ b, f b a ∂μ = ⨅ b, ∫⁻ (a : α), f b a ∂μ

case intro.inr
α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : Countable β
f : β → α → ℝ≥0∞
μ : Measure α
hμ : μ ≠ 0
hf : ∀ (b : β), Measurable (f b)
hf_int : ∀ (b : β), ∫⁻ (a : α), f b a ∂μ ≠ ∞
h_directed : Directed (fun x1 x2 ↦ x1 ≥ x2) f
val✝ : Encodable β
h✝ : Nonempty β
⊢ ∫⁻ (a : α), ⨅ b, f b a ∂μ = ⨅ b, ∫⁻ (a : α), f b a ∂μ
Module: Mathlib.MeasureTheory.Measure.Decomposition.Exhaustion

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝ : IsFiniteMeasure ν
this : ∀ (n : ℕ), SigmaFinite (μ.restrict (μ.sigmaFiniteSetGE ν n))
f : ℕ × ℕ → Set α :=
  fun p ↦
    (μ.sigmaFiniteSetWRT' ν)ᶜ ∪ spanningSets (μ.restrict (μ.sigmaFiniteSetGE ν p.1)) p.2 ∩ μ.sigmaFiniteSetGE ν p.1
⊢ SigmaFinite (μ.restrict (μ.sigmaFiniteSetWRT' ν))

Tactic:
suffices (μ.restrict (μ.sigmaFiniteSetWRT' ν)).FiniteSpanningSetsIn (Set.range f) from
    this.sigmaFinite

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝ : IsFiniteMeasure ν
this : ∀ (n : ℕ), SigmaFinite (μ.restrict (μ.sigmaFiniteSetGE ν n))
f : ℕ × ℕ → Set α :=
  fun p ↦
    (μ.sigmaFiniteSetWRT' ν)ᶜ ∪ spanningSets (μ.restrict (μ.sigmaFiniteSetGE ν p.1)) p.2 ∩ μ.sigmaFiniteSetGE ν p.1
⊢ (μ.restrict (μ.sigmaFiniteSetWRT' ν)).FiniteSpanningSetsIn (Set.range f)
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
f : α → β
g : α → γ
g' : γ → β
mα : MeasurableSpace α
mγ : MeasurableSpace γ
inst✝ : TopologicalSpace β
hg : MeasurableEmbedding g
hf : StronglyMeasurable f
hg' : StronglyMeasurable g'
x : γ
⊢ Tendsto (fun n ↦ ((fun n ↦ (hf.approx n).extend g hg (hg'.approx n)) n) x) atTop (𝓝 (Function.extend g f g' x))

Tactic:
by_cases hx : ∃ y, g y = x

Goal state after:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
f : α → β
g : α → γ
g' : γ → β
mα : MeasurableSpace α
mγ : MeasurableSpace γ
inst✝ : TopologicalSpace β
hg : MeasurableEmbedding g
hf : StronglyMeasurable f
hg' : StronglyMeasurable g'
x : γ
hx : ∃ y, g y = x
⊢ Tendsto (fun n ↦ ((fun n ↦ (hf.approx n).extend g hg (hg'.approx n)) n) x) atTop (𝓝 (Function.extend g f g' x))

case neg
α : Type u_1
β : Type u_2
γ : Type u_3
f : α → β
g : α → γ
g' : γ → β
mα : MeasurableSpace α
mγ : MeasurableSpace γ
inst✝ : TopologicalSpace β
hg : MeasurableEmbedding g
hf : StronglyMeasurable f
hg' : StronglyMeasurable g'
x : γ
hx : ¬∃ y, g y = x
⊢ Tendsto (fun n ↦ ((fun n ↦ (hf.approx n).extend g hg (hg'.approx n)) n) x) atTop (𝓝 (Function.extend g f g' x))
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝ : TopologicalSpace β
f : α → β
s t : Set α
hs : MeasurableSet s
ht : MeasurableSet t
h : univ ⊆ s ∪ t
hc : StronglyMeasurable fun a ↦ f ↑a
hd : StronglyMeasurable fun a ↦ f ↑a
a✝ : Nontrivial β
inhabited_h : Inhabited β
⊢ StronglyMeasurable f

Tactic:
suffices Function.extend Subtype.val (fun x : s ↦ f x)
      (Function.extend (↑) (fun x : t ↦ f x) fun _ ↦ default) = f from
    this ▸ (MeasurableEmbedding.subtype_coe hs).stronglyMeasurable_extend hc <|
      (MeasurableEmbedding.subtype_coe ht).stronglyMeasurable_extend hd stronglyMeasurable_const

Goal state after:
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝ : TopologicalSpace β
f : α → β
s t : Set α
hs : MeasurableSet s
ht : MeasurableSet t
h : univ ⊆ s ∪ t
hc : StronglyMeasurable fun a ↦ f ↑a
hd : StronglyMeasurable fun a ↦ f ↑a
a✝ : Nontrivial β
inhabited_h : Inhabited β
⊢ Function.extend Subtype.val (fun x ↦ f ↑x) (Function.extend Subtype.val (fun x ↦ f ↑x) fun x ↦ default) = f
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case const
α : Type u_1
β : Type u_2
inst✝² : MeasurableSpace α
inst✝¹ : Nonempty β
inst✝ : TopologicalSpace β
P : (f : α → β) → StronglyMeasurable f → Prop
const : ∀ (c : β), P (fun x ↦ c) ⋯
pcw :
  ∀ ⦃f g : α → β⦄ {s : Set α} (hf : StronglyMeasurable f) (hg : StronglyMeasurable g) (hs : MeasurableSet s),
    P f hf → P g hg → P (s.piecewise f g) ⋯
lim :
  ∀ ⦃f : ℕ → α → β⦄ ⦃g : α → β⦄ (hf : ∀ (n : ℕ), StronglyMeasurable (f n)) (hg : StronglyMeasurable g),
    (∀ (n : ℕ), P (f n) ⋯) → (∀ (x : α), Tendsto (fun x_1 ↦ f x_1 x) atTop (𝓝 (g x))) → P g hg
f : α → β
hf : StronglyMeasurable f
s : ℕ → α →ₛ β := hf.approx
n : ℕ
c : β
⊢ P ⇑(SimpleFunc.const α c) ⋯

Tactic:
exact const c

Goal state after:
Module: Mathlib.Analysis.Normed.Group.InfiniteSum

Goal state before:
pp: ι : Type u_1
E : Type u_3
inst✝ : SeminormedAddCommGroup E
f : ι → E
⊢ (∀ (i : ℝ), 0 < i → ∃ s, ∀ (t : Finset ι), Disjoint t s → ∑ b ∈ t, f b ∈ ball 0 i) ↔
    ∀ ε > 0, ∃ s, ∀ (t : Finset ι), Disjoint t s → ‖∑ i ∈ t, f i‖ < ε

pp: ι : Type u_1
E : Type u_3
inst✝ : SeminormedAddCommGroup E
f : ι → E
⊢ ∀ ⦃s t : Set E⦄,
    s ⊆ t →
      (∃ s_1, ∀ (t : Finset ι), Disjoint t s_1 → ∑ b ∈ t, f b ∈ s) →
        ∃ s, ∀ (t_1 : Finset ι), Disjoint t_1 s → ∑ b ∈ t_1, f b ∈ t

Tactic:
· simp only [ball_zero_eq, Set.mem_ofPred_eq]

Goal state after:
ι : Type u_1
E : Type u_3
inst✝ : SeminormedAddCommGroup E
f : ι → E
⊢ ∀ ⦃s t : Set E⦄,
    s ⊆ t →
      (∃ s_1, ∀ (t : Finset ι), Disjoint t s_1 → ∑ b ∈ t, f b ∈ s) →
        ∃ s, ∀ (t_1 : Finset ι), Disjoint t_1 s → ∑ b ∈ t_1, f b ∈ t
Module: Mathlib.Topology.UnitInterval

Goal state before:
pp: x : ↑I
⊢ Subtype.val ⁻¹' Iio ↑x = Ico 0 x

Tactic:
by
  rw [preimage_subtype_val_Iio]
  exact Ico_bot.symm

Goal state after:
Module: Mathlib.Topology.UnitInterval

Goal state before:
pp: α : Type u_1
inst✝² : AddCommGroup α
inst✝¹ : LinearOrder α
inst✝ : IsOrderedAddMonoid α
a b : α
h : a ≤ b
δ : α
hδ : 0 ≤ δ
t : ↑(Icc a b)
n : ℕ
ht : t ∈ Icc (addNSMul h δ n) (addNSMul h δ (n + 1))
⊢ |δ + n • δ - n • δ| ≤ δ

Tactic:
add_sub_cancel_right

Goal state after:
α : Type u_1
inst✝² : AddCommGroup α
inst✝¹ : LinearOrder α
inst✝ : IsOrderedAddMonoid α
a b : α
h : a ≤ b
δ : α
hδ : 0 ≤ δ
t : ↑(Icc a b)
n : ℕ
ht : t ∈ Icc (addNSMul h δ n) (addNSMul h δ (n + 1))
⊢ |δ| ≤ δ
Module: Mathlib.Topology.Metrizable.CompletelyMetrizable

Goal state before:
pp: case inr
X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : DiscreteTopology X
x y : X
h : x ≠ y
⊢ (if x = y then 0 else 1) = if y = x then 0 else 1

Tactic:
simp [h, h.symm]

Goal state after:
Module: Mathlib.Topology.MetricSpace.Gluing

Goal state before:
pp: X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
x : X
y : Y
⊢ 1 ≤ Sum.dist (Sum.inl x) (Sum.inr y)

Tactic:
exact Sum.one_le_dist_inl_inr

Goal state after:
Module: Mathlib.Topology.Metrizable.CompletelyMetrizable

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : DiscreteTopology X
m : MetricSpace X :=
  { dist := fun x y ↦ if x = y then 0 else 1, dist_self := ⋯, dist_comm := ⋯, dist_triangle := ⋯, edist_dist := ⋯,
    uniformity_dist := ⋯, cobounded_sets := ⋯, eq_of_dist_eq_zero := ⋯ }
x : X
⊢ {x} = Metric.ball x 1

Tactic:
refine subset_antisymm (singleton_subset_iff.2 (Metric.mem_ball_self (by simp)))
      fun y hy ↦ ?_

Goal state after:
X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : DiscreteTopology X
m : MetricSpace X :=
  { dist := fun x y ↦ if x = y then 0 else 1, dist_self := ⋯, dist_comm := ⋯, dist_triangle := ⋯, edist_dist := ⋯,
    uniformity_dist := ⋯, cobounded_sets := ⋯, eq_of_dist_eq_zero := ⋯ }
x y : X
hy : y ∈ Metric.ball x 1
⊢ y ∈ {x}
Module: Mathlib.Topology.Metrizable.CompletelyMetrizable

Goal state before:
pp: case refine_2
X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : DiscreteTopology X
m : MetricSpace X :=
  { dist := fun x y ↦ if x = y then 0 else 1, dist_self := ⋯, dist_comm := ⋯, dist_triangle := ⋯, edist_dist := ⋯,
    uniformity_dist := ⋯, cobounded_sets := ⋯, eq_of_dist_eq_zero := ⋯ }
u : ℕ → X
hu : CauchySeq u
⊢ ∃ a, Tendsto u atTop (𝓝 a)

Tactic:
rw [Metric.cauchySeq_iff'] at hu

Goal state after:
case refine_2
X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : DiscreteTopology X
m : MetricSpace X :=
  { dist := fun x y ↦ if x = y then 0 else 1, dist_self := ⋯, dist_comm := ⋯, dist_triangle := ⋯, edist_dist := ⋯,
    uniformity_dist := ⋯, cobounded_sets := ⋯, eq_of_dist_eq_zero := ⋯ }
u : ℕ → X
hu : ∀ ε > 0, ∃ N, ∀ n ≥ N, dist (u n) (u N) < ε
⊢ ∃ a, Tendsto u atTop (𝓝 a)
Module: Mathlib.Topology.MetricSpace.CantorScheme

Goal state before:
pp: β : Type u_1
α : Type u_2
A : List β → Set α
inst✝² : PseudoMetricSpace α
inst✝¹ : TopologicalSpace β
inst✝ : DiscreteTopology β
hA : VanishingDiam A
x : ↑(inducedMap A).fst
ε : ℝ
ε_pos : ε > 0
⊢ ∀ᶠ (x_1 : ↑(inducedMap A).fst) in 𝓝 x, dist ((inducedMap A).snd x_1) ((inducedMap A).snd x) < ε

Tactic:
obtain ⟨n, hn⟩ := hA.dist_lt _ ε_pos x

Goal state after:
β : Type u_1
α : Type u_2
A : List β → Set α
inst✝² : PseudoMetricSpace α
inst✝¹ : TopologicalSpace β
inst✝ : DiscreteTopology β
hA : VanishingDiam A
x : ↑(inducedMap A).fst
ε : ℝ
ε_pos : ε > 0
n : ℕ
hn : ∀ y ∈ A (res (↑x) n), ∀ z ∈ A (res (↑x) n), dist y z < ε
⊢ ∀ᶠ (x_1 : ↑(inducedMap A).fst) in 𝓝 x, dist ((inducedMap A).snd x_1) ((inducedMap A).snd x) < ε
Module: Mathlib.Topology.MetricSpace.PiNat

Goal state before:
pp: case mp
E : ℕ → Type u_1
inst✝¹ : (n : ℕ) → TopologicalSpace (E n)
inst✝ : ∀ (n : ℕ), DiscreteTopology (E n)
s : Set ((n : ℕ) → E n)
⊢ IsOpen[Pi.topologicalSpace] s → ∀ x ∈ s, ∃ ε > 0, ∀ (y : (n : ℕ) → E n), dist x y < ε → y ∈ s

Tactic:
intro hs x hx
    obtain ⟨v, ⟨y, n, rfl⟩, h'x, h's⟩ :
        ∃ v ∈ { s | ∃ (x : ∀ n : ℕ, E n) (n : ℕ), s = cylinder x n }, x ∈ v ∧ v ⊆ s :=
      (isTopologicalBasis_cylinders E).exists_subset_of_mem_open hx hs
    rw [← mem_cylinder_iff_eq.1 h'x] at h's
    exact
      ⟨(1 / 2 : ℝ) ^ n, by simp, fun y hy => h's fun i hi => (apply_eq_of_dist_lt hy hi.le).symm⟩

Goal state after:
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: α : Type u_1
inst✝² : TopologicalSpace α
β : Type u_3
inst✝¹ : TopologicalSpace β
inst✝ : PolishSpace β
f : β → α
f_cont : Continuous[inst✝¹, inst✝²] f
⊢ AnalyticSet (range f)

Tactic:
cases isEmpty_or_nonempty β

Goal state after:
case inl
α : Type u_1
inst✝² : TopologicalSpace α
β : Type u_3
inst✝¹ : TopologicalSpace β
inst✝ : PolishSpace β
f : β → α
f_cont : Continuous[inst✝¹, inst✝²] f
h✝ : IsEmpty β
⊢ AnalyticSet (range f)

case inr
α : Type u_1
inst✝² : TopologicalSpace α
β : Type u_3
inst✝¹ : TopologicalSpace β
inst✝ : PolishSpace β
f : β → α
f_cont : Continuous[inst✝¹, inst✝²] f
h✝ : Nonempty β
⊢ AnalyticSet (range f)
Module: Mathlib.MeasureTheory.Measure.MutuallySingular

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
ν : Measure α
ι : Type u_2
inst✝ : Countable ι
μ : ι → Measure α
s : ι → Set α
hsm : ∀ (i : ι), MeasurableSet (s i)
hsμ : ∀ (i : ι), (μ i) (s i) = 0
hsν : ∀ (i : ι), ν (s i)ᶜ = 0
⊢ sum μ ⟂ₘ ν

Tactic:
refine ⟨⋂ i, s i, MeasurableSet.iInter hsm, ?_, ?_⟩

Goal state after:
case refine_1
α : Type u_1
m0 : MeasurableSpace α
ν : Measure α
ι : Type u_2
inst✝ : Countable ι
μ : ι → Measure α
s : ι → Set α
hsm : ∀ (i : ι), MeasurableSet (s i)
hsμ : ∀ (i : ι), (μ i) (s i) = 0
hsν : ∀ (i : ι), ν (s i)ᶜ = 0
⊢ (sum μ) (⋂ i, s i) = 0

case refine_2
α : Type u_1
m0 : MeasurableSpace α
ν : Measure α
ι : Type u_2
inst✝ : Countable ι
μ : ι → Measure α
s : ι → Set α
hsm : ∀ (i : ι), MeasurableSet (s i)
hsμ : ∀ (i : ι), (μ i) (s i) = 0
hsν : ∀ (i : ι), ν (s i)ᶜ = 0
⊢ ν (⋂ i, s i)ᶜ = 0
Module: Mathlib.MeasureTheory.Measure.MutuallySingular

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
s : Set α
hs : μ sᶜ = 0
t : Set α
ht : ν tᶜ = 0
hst : Disjoint s t
⊢ μ ⊓ ν ≤ ⊥

Tactic:
have : (⊥ : Measure α) = 0 := rfl

Goal state after:
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
s : Set α
hs : μ sᶜ = 0
t : Set α
ht : ν tᶜ = 0
hst : Disjoint s t
this : ⊥ = 0
⊢ μ ⊓ ν ≤ ⊥
Module: Mathlib.MeasureTheory.Measure.Dirac

Goal state before:
pp: α : Type u_4
mα : MeasurableSpace α
inst✝ : MeasurableSingletonClass α
μ : Measure α
a₁ a₂ : α
ha : a₁ ≠ a₂
⊢ (∀ᵐ (a : α) ∂μ, a = a₁ ∨ a = a₂) ↔ μ = μ {a₁} • dirac a₁ + μ {a₂} • dirac a₂

Tactic:
convert! ae_mem_finset_iff (s := .cons a₁ { a₂ } <| by simpa) <;> simp

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Countable

Goal state before:
pp: α : Type u_1
inst✝¹ : MeasurableSpace α
μ✝ : Measure α
f : α → ℝ≥0∞
μ : Measure α
inst✝ : SFinite μ
h : IsFiniteMeasure μ
g : ℕ → α → ℝ≥0∞
hgm : ∀ (n : ℕ), Measurable (g n)
hgf : ∀ (n : ℕ), g n ≤ f
hgle : ∀ (n : ℕ), g n ≤ ↑n
hgint : ∀ (n : ℕ), ∫⁻ (a : α), min (f a) ↑n ∂μ = ∫⁻ (a : α), g n a ∂μ
φ : α → ℝ≥0∞ := fun x ↦ ⨆ n, g n x
hφm : Measurable φ
hφle : φ ≤ f
s : Set α
⊢ ⨆ φ, ⨆ (_ : ∀ (x : α), ↑(φ x) ≤ f x), (SimpleFunc.map ofNNReal φ).lintegral (μ.restrict s) ≤ ∫⁻ (a : α) in s, φ a ∂μ

Tactic:
refine iSup₂_le fun ψ hψ ↦ ?_

Goal state after:
α : Type u_1
inst✝¹ : MeasurableSpace α
μ✝ : Measure α
f : α → ℝ≥0∞
μ : Measure α
inst✝ : SFinite μ
h : IsFiniteMeasure μ
g : ℕ → α → ℝ≥0∞
hgm : ∀ (n : ℕ), Measurable (g n)
hgf : ∀ (n : ℕ), g n ≤ f
hgle : ∀ (n : ℕ), g n ≤ ↑n
hgint : ∀ (n : ℕ), ∫⁻ (a : α), min (f a) ↑n ∂μ = ∫⁻ (a : α), g n a ∂μ
φ : α → ℝ≥0∞ := fun x ↦ ⨆ n, g n x
hφm : Measurable φ
hφle : φ ≤ f
s : Set α
ψ : SimpleFunc α ℝ≥0
hψ : ∀ (x : α), ↑(ψ x) ≤ f x
⊢ (SimpleFunc.map ofNNReal ψ).lintegral (μ.restrict s) ≤ ∫⁻ (a : α) in s, φ a ∂μ
Module: Mathlib.MeasureTheory.Measure.Doubling

Goal state before:
pp: α : Type u_1
inst✝² : PseudoMetricSpace α
inst✝¹ : MeasurableSpace α
μ : Measure α
inst✝ : IsUnifLocDoublingMeasure μ
K : ℝ
C : ℝ≥0 := doublingConstant μ
this : ∀ (n : ℕ), ∀ᶠ (ε : ℝ) in 𝓝[>] 0, ∀ (x : α), μ (closedBall x (2 ^ n * ε)) ≤ ↑C ^ n * μ (closedBall x ε)
n : ℕ
hn : K < 2 ^ n
⊢ ∃ C, ∀ᶠ (ε : ℝ) in 𝓝[>] 0, ∀ (x : α), ∀ t ≤ K, μ (closedBall x (t * ε)) ≤ ↑C * μ (closedBall x ε)

Tactic:
use C ^ n

Goal state after:
case h
α : Type u_1
inst✝² : PseudoMetricSpace α
inst✝¹ : MeasurableSpace α
μ : Measure α
inst✝ : IsUnifLocDoublingMeasure μ
K : ℝ
C : ℝ≥0 := ⋯
this : ∀ (n : ℕ), ∀ᶠ (ε : ℝ) in 𝓝[>] 0, ∀ (x : α), μ (closedBall x (2 ^ n * ε)) ≤ ↑C ^ n * μ (closedBall x ε)
n : ℕ
hn : K < 2 ^ n
⊢ ∀ᶠ (ε : ℝ) in 𝓝[>] 0, ∀ (x : α), ∀ t ≤ K, μ (closedBall x (t * ε)) ≤ ↑(C ^ n) * μ (closedBall x ε)