mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Normed.Module.RieszLemma

Goal state before:
pp: 𝕜 : Type u_4
inst✝² : RCLike 𝕜
E : Type u_5
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
F : Subspace 𝕜 E
hFc : IsClosed[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑F
hF : ∃ x, x ∉ F
r : ℝ
hr : r < 1
⊢ ∃ x₀ ∉ F, ‖x₀‖ = 1 ∧ ∀ y ∈ F, r ≤ ‖x₀ - y‖

Tactic:
obtain ⟨x₀, hx₀, h⟩ := riesz_lemma hFc hF hr

Goal state after:
𝕜 : Type u_4
inst✝² : RCLike 𝕜
E : Type u_5
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
F : Subspace 𝕜 E
hFc : IsClosed[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑F
hF : ∃ x, x ∉ F
r : ℝ
hr : r < 1
x₀ : E
hx₀ : x₀ ∉ F
h : ∀ y ∈ F, r * ‖x₀‖ ≤ ‖x₀ - y‖
⊢ ∃ x₀ ∉ F, ‖x₀‖ = 1 ∧ ∀ y ∈ F, r ≤ ‖x₀ - y‖
Module: Mathlib.MeasureTheory.Integral.Bochner.SumMeasure

Goal state before:
pp: case hs
X : Type u_2
E : Type u_3
mX : MeasurableSpace X
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : MeasurableSingletonClass X
μ : Measure X
f : X → E
s : Set X
hs : s.Countable
hf : Integrable f (μ.restrict s)
hi : Countable { x // x ∈ s }
⊢ MeasurableSet s

Tactic:
· exact Countable.measurableSet hs

Goal state after:
Module: Mathlib.MeasureTheory.Integral.SetToL1

Goal state before:
pp: α : Type u_1
E : Type u_2
F : Type u_3
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
m : MeasurableSpace α
μ : Measure α
T : Set α → E →L[ℝ] F
C : ℝ
hT : DominatedFinMeasAdditive μ T C
ι : Type u_7
s : Finset ι
f : ι → α → E
⊢ (∀ i ∈ s, Integrable (f i) μ) → setToFun μ T hT (∑ i ∈ s, f i) = ∑ i ∈ s, setToFun μ T hT (f i)

Tactic:
refine Finset.induction_on s ?_ ?_

Goal state after:
case refine_1
α : Type u_1
E : Type u_2
F : Type u_3
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
m : MeasurableSpace α
μ : Measure α
T : Set α → E →L[ℝ] F
C : ℝ
hT : DominatedFinMeasAdditive μ T C
ι : Type u_7
s : Finset ι
f : ι → α → E
⊢ (∀ i ∈ ∅, Integrable (f i) μ) → setToFun μ T hT (∑ i ∈ ∅, f i) = ∑ i ∈ ∅, setToFun μ T hT (f i)

case refine_2
α : Type u_1
E : Type u_2
F : Type u_3
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
m : MeasurableSpace α
μ : Measure α
T : Set α → E →L[ℝ] F
C : ℝ
hT : DominatedFinMeasAdditive μ T C
ι : Type u_7
s : Finset ι
f : ι → α → E
⊢ ∀ (a : ι) (s : Finset ι),
    a ∉ s →
      ((∀ i ∈ s, Integrable (f i) μ) → setToFun μ T hT (∑ i ∈ s, f i) = ∑ i ∈ s, setToFun μ T hT (f i)) →
        (∀ i ∈ insert a s, Integrable (f i) μ) →
          setToFun μ T hT (∑ i ∈ insert a s, f i) = ∑ i ∈ insert a s, setToFun μ T hT (f i)
Module: Mathlib.Analysis.Normed.Module.FiniteDimension

Goal state before:
pp: E' : Type u_1
inst✝² : NormedAddCommGroup E'
inst✝¹ : NormedSpace ℝ E'
inst✝ : FiniteDimensional ℝ E'
⊢ 0 < lipschitzExtensionConstant E'

Tactic:
by
  rw [lipschitzExtensionConstant]
  exact zero_lt_one.trans_le (le_max_right _ _)

Goal state after:
Module: Mathlib.Topology.ContinuousMap.Bounded.Normed

Goal state before:
pp: α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : SeminormedAddCommGroup β
inst✝ : Nonempty α
f : α →ᵇ β
M : ℝ
⊢ ‖f‖ ≤ M ↔ ∀ (x : α), ‖f x‖ ≤ M

Tactic:
norm_def,

Goal state after:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : SeminormedAddCommGroup β
inst✝ : Nonempty α
f : α →ᵇ β
M : ℝ
⊢ dist f 0 ≤ M ↔ ∀ (x : α), ‖f x‖ ≤ M
Module: Mathlib.Topology.ContinuousMap.Bounded.Normed

Goal state before:
pp: α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : SeminormedAddCommGroup β
inst✝ : CompactSpace α
f : α →ᵇ β
M : ℝ
M0 : 0 < M
⊢ ‖f‖ < M ↔ ∀ (x : α), ‖f x‖ < M

Tactic:
norm_def,

Goal state after:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : SeminormedAddCommGroup β
inst✝ : CompactSpace α
f : α →ᵇ β
M : ℝ
M0 : 0 < M
⊢ dist f 0 < M ↔ ∀ (x : α), ‖f x‖ < M
Module: Mathlib.Topology.ContinuousMap.Bounded.Normed

Goal state before:
pp: α : Type u
β : Type v
inst✝³ : TopologicalSpace α
inst✝² : SeminormedAddCommGroup β
inst✝¹ : Nonempty α
inst✝ : CompactSpace α
f : α →ᵇ β
M : ℝ
⊢ ‖f‖ < M ↔ ∀ (x : α), ‖f x‖ < M

Tactic:
norm_def,

Goal state after:
α : Type u
β : Type v
inst✝³ : TopologicalSpace α
inst✝² : SeminormedAddCommGroup β
inst✝¹ : Nonempty α
inst✝ : CompactSpace α
f : α →ᵇ β
M : ℝ
⊢ dist f 0 < M ↔ ∀ (x : α), ‖f x‖ < M
Module: Mathlib.Topology.ContinuousMap.Bounded.Normed

Goal state before:
pp: α : Type u
β : Type v
inst✝¹ : TopologicalSpace α
inst✝ : SeminormedAddCommGroup β
f : α →ᵇ β
⊢ ‖f‖ = ⨆ x, ‖f x‖

Tactic:
norm_def,

Goal state after:
α : Type u
β : Type v
inst✝¹ : TopologicalSpace α
inst✝ : SeminormedAddCommGroup β
f : α →ᵇ β
⊢ dist f 0 = ⨆ x, ‖f x‖
Module: Mathlib.Topology.ContinuousMap.Bounded.Normed

Goal state before:
pp: α : Type u
β : Type v
γ : Type w
inst✝⁴ : TopologicalSpace α
inst✝³ : NormedAddCommGroup β
inst✝² : Lattice β
inst✝¹ : HasSolidNorm β
inst✝ : IsOrderedAddMonoid β
f g : α →ᵇ β
C₁ C₂ : ℝ
x y : α
hf : ∀ (x y : α), ‖f x - f y‖ ≤ C₁
hg : ∀ (x y : α), ‖g x - g y‖ ≤ C₂
⊢ ‖(⇑f ⊓ ⇑g) x - (⇑f ⊓ ⇑g) y‖ ≤ C₁ + C₂

Tactic:
exact (norm_inf_sub_inf_le_add_norm _ _ _ _).trans (add_le_add (hf _ _) (hg _ _))

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

Goal state before:
pp: α : Type u_1
inst✝¹ : PseudoEMetricSpace α
β : Type u_2
inst✝ : One β
f : α → β
E : Set α
x : α
x_mem_closure : x ∈ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E
δ : ℝ
a✝ : δ ∈ univ
obs : x ∈ cthickening δ E
⊢ (cthickening δ E).mulIndicator f x =
    (closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E).mulIndicator f x

Tactic:
mulIndicator_of_mem obs f,

Goal state after:
α : Type u_1
inst✝¹ : PseudoEMetricSpace α
β : Type u_2
inst✝ : One β
f : α → β
E : Set α
x : α
x_mem_closure : x ∈ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E
δ : ℝ
a✝ : δ ∈ univ
obs : x ∈ cthickening δ E
⊢ f x = (closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E).mulIndicator f x
Module: Mathlib.MeasureTheory.Integral.SetToL1

Goal state before:
pp: α : Type u_1
E : Type u_2
F✝ : Type u_3
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
inst✝² : NormedAddCommGroup F✝
inst✝¹ : NormedSpace ℝ F✝
m : MeasurableSpace α
μ : Measure α
T : Set α → E →L[ℝ] F✝
C : ℝ
hT : DominatedFinMeasAdditive μ T C
ι : Type u_7
inst✝ : Countable ι
F : ι → α → E
f : α → E
bound : ι → α → ℝ
hF_meas : ∀ (n : ι), AEStronglyMeasurable (F n) μ
h_bound : ∀ (n : ι), ∀ᵐ (a : α) ∂μ, ‖F n a‖ ≤ bound n a
bound_summable : ∀ᵐ (a : α) ∂μ, Summable fun n ↦ bound n a
bound_integrable : Integrable (fun a ↦ ∑' (n : ι), bound n a) μ
h_lim : ∀ᵐ (a : α) ∂μ, HasSum (fun n ↦ F n a) (f a)
hb_nonneg : ∀ᵐ (a : α) ∂μ, ∀ (n : ι), 0 ≤ bound n a
hb_le_tsum : ∀ (n : ι), bound n ≤ᵐ[μ] fun a ↦ ∑' (n : ι), bound n a
hF_integrable : ∀ (n : ι), Integrable (F n) μ
⊢ HasSum (fun n ↦ setToFun μ T hT (F n)) (setToFun μ T hT f)

Tactic:
simp only [HasSum, ← setToFun_finsetSum _ _ fun n _ => hF_integrable n]

Goal state after:
α : Type u_1
E : Type u_2
F✝ : Type u_3
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
inst✝² : NormedAddCommGroup F✝
inst✝¹ : NormedSpace ℝ F✝
m : MeasurableSpace α
μ : Measure α
T : Set α → E →L[ℝ] F✝
C : ℝ
hT : DominatedFinMeasAdditive μ T C
ι : Type u_7
inst✝ : Countable ι
F : ι → α → E
f : α → E
bound : ι → α → ℝ
hF_meas : ∀ (n : ι), AEStronglyMeasurable (F n) μ
h_bound : ∀ (n : ι), ∀ᵐ (a : α) ∂μ, ‖F n a‖ ≤ bound n a
bound_summable : ∀ᵐ (a : α) ∂μ, Summable fun n ↦ bound n a
bound_integrable : Integrable (fun a ↦ ∑' (n : ι), bound n a) μ
h_lim : ∀ᵐ (a : α) ∂μ, HasSum (fun n ↦ F n a) (f a)
hb_nonneg : ∀ᵐ (a : α) ∂μ, ∀ (n : ι), 0 ≤ bound n a
hb_le_tsum : ∀ (n : ι), bound n ≤ᵐ[μ] fun a ↦ ∑' (n : ι), bound n a
hF_integrable : ∀ (n : ι), Integrable (F n) μ
⊢ Tendsto (fun s ↦ setToFun μ T hT fun a ↦ ∑ i ∈ s, F i a) (SummationFilter.unconditional ι).filter
    (𝓝 (setToFun μ T hT f))
Module: Mathlib.MeasureTheory.Integral.SetToL1

Goal state before:
pp: α : Type u_1
E : Type u_2
F✝ : Type u_3
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
inst✝² : NormedAddCommGroup F✝
inst✝¹ : NormedSpace ℝ F✝
m : MeasurableSpace α
μ : Measure α
T : Set α → E →L[ℝ] F✝
C : ℝ
hT : DominatedFinMeasAdditive μ T C
ι : Type u_7
inst✝ : Countable ι
F : ι → α → E
f : α → E
bound : ι → α → ℝ
hF_meas : ∀ (n : ι), AEStronglyMeasurable (F n) μ
h_bound : ∀ (n : ι), ∀ᵐ (a : α) ∂μ, ‖F n a‖ ≤ bound n a
bound_summable : ∀ᵐ (a : α) ∂μ, Summable fun n ↦ bound n a
bound_integrable : Integrable (fun a ↦ ∑' (n : ι), bound n a) μ
h_lim : ∀ᵐ (a : α) ∂μ, HasSum (fun n ↦ F n a) (f a)
hb_nonneg : ∀ᵐ (a : α) ∂μ, ∀ (n : ι), 0 ≤ bound n a
hb_le_tsum : ∀ (n : ι), bound n ≤ᵐ[μ] fun a ↦ ∑' (n : ι), bound n a
hF_integrable : ∀ (n : ι), Integrable (F n) μ
s : Finset ι
a : α
hFa : ∀ (i : ι), ‖F i a‖ ≤ bound i a
ha0 : ∀ (n : ι), 0 ≤ bound n a
has : Summable fun n ↦ bound n a
⊢ ‖∑ i ∈ s, F i a‖ ≤ ∑' (n : ι), bound n a

Tactic:
calc
      ‖∑ n ∈ s, F n a‖ ≤ ∑ n ∈ s, bound n a := norm_sum_le_of_le _ fun n _ => hFa n
      _ ≤ ∑' n, bound n a := has.sum_le_tsum _ (fun n _ => ha0 n)

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

Goal state before:
pp: R : Type u_1
inst✝⁴ : LinearOrder R
inst✝³ : TopologicalSpace R
f : StieltjesFunction R
inst✝² : OrderTopology R
inst✝¹ : CompactIccSpace R
inst✝ : DenselyOrdered R
a b : R
hab : a < b
s : ℕ → Set R
hs : Ioc a b ⊆ ⋃ i, s i
ε : ℝ≥0
εpos : 0 < ε
h : ∑' (i : ℕ), f.length (s i) < ∞
δ : ℝ≥0 := ε / 2
δpos : 0 < ↑δ
ε' : ℕ → ℝ≥0
ε'0 : ∀ (i : ℕ), 0 < ε' i
hε : ∑' (i : ℕ), ↑(ε' i) < ↑δ
A : ContinuousWithinAt (fun r ↦ ↑f r - ↑f a) (Ioi a) a
⊢ 0 < δ

Tactic:
← ENNReal.coe_pos

Goal state after:
R : Type u_1
inst✝⁴ : LinearOrder R
inst✝³ : TopologicalSpace R
f : StieltjesFunction R
inst✝² : OrderTopology R
inst✝¹ : CompactIccSpace R
inst✝ : DenselyOrdered R
a b : R
hab : a < b
s : ℕ → Set R
hs : Ioc a b ⊆ ⋃ i, s i
ε : ℝ≥0
εpos : 0 < ε
h : ∑' (i : ℕ), f.length (s i) < ∞
δ : ℝ≥0 := ε / 2
δpos : 0 < ↑δ
ε' : ℕ → ℝ≥0
ε'0 : ∀ (i : ℕ), 0 < ε' i
hε : ∑' (i : ℕ), ↑(ε' i) < ↑δ
A : ContinuousWithinAt (fun r ↦ ↑f r - ↑f a) (Ioi a) a
⊢ 0 < ↑δ
Module: Mathlib.MeasureTheory.Measure.Content

Goal state before:
pp: case e'_3
G : Type w
inst✝¹ : TopologicalSpace G
μ : Content G
inst✝ : R1Space G
U : ℕ → Opens G
h3 : ∀ (t : Finset ℕ) (K : ℕ → Compacts G), μ (t.sup K) ≤ ∑ i ∈ t, μ (K i)
K : Compacts G
hK : ↑K ⊆ ↑(⨆ i, U i)
t : Finset ℕ
ht : ↑K ⊆ ⋃ i ∈ t, ↑(U i)
K' : ℕ → Set G
h1K' : ∀ (i : ℕ), IsCompact (K' i)
h2K' : ∀ (i : ℕ), K' i ⊆ (SetLike.coe ∘ U) i
h3K' : ↑K = ⋃ i ∈ t, K' i
L : ℕ → Compacts G := ⋯
⊢ ↑K = ↑(t.sup L)

Tactic:
Compacts.coe_finset_sup,

Goal state after:
case e'_3
G : Type w
inst✝¹ : TopologicalSpace G
μ : Content G
inst✝ : R1Space G
U : ℕ → Opens G
h3 : ∀ (t : Finset ℕ) (K : ℕ → Compacts G), μ (t.sup K) ≤ ∑ i ∈ t, μ (K i)
K : Compacts G
hK : ↑K ⊆ ↑(⨆ i, U i)
t : Finset ℕ
ht : ↑K ⊆ ⋃ i ∈ t, ↑(U i)
K' : ℕ → Set G
h1K' : ∀ (i : ℕ), IsCompact (K' i)
h2K' : ∀ (i : ℕ), K' i ⊆ (SetLike.coe ∘ U) i
h3K' : ↑K = ⋃ i ∈ t, K' i
L : ℕ → Compacts G := fun n ↦ { carrier := K' n, isCompact' := ⋯ }
⊢ ↑K = t.sup fun i ↦ ↑(L i)
Module: Mathlib.MeasureTheory.Measure.Content

Goal state before:
pp: G : Type w
inst✝² : TopologicalSpace G
μ : Content G
inst✝¹ : Group G
inst✝ : IsTopologicalGroup G
h3 : ∀ (g : G) {K : Compacts G}, μ (Compacts.map (fun x ↦ g * x) ⋯ K) = μ K
K : Compacts G
hK : μ K ≠ 0
U : Opens G
hU : (↑U).Nonempty
⊢ 0 < μ.innerContent U

Tactic:
have : (interior (U : Set G)).Nonempty := by rwa [U.isOpen.interior_eq]
  rcases compact_covered_by_mul_left_translates K.2 this with ⟨s, hs⟩
  suffices μ K ≤ s.card * μ.innerContent U by
    exact (ENNReal.mul_pos_iff.mp <| hK.bot_lt.trans_le this).2
  have : (K : Set G) ⊆ ↑(⨆ g ∈ s, Opens.comap (Homeomorph.mulLeft g : C(G, G)) U) := by
    simpa only [Opens.iSup_def, Opens.coe_comap, Subtype.coe_mk]
  refine (μ.le_innerContent _ _ this).trans ?_
  refine
    (rel_iSup_sum μ.innerContent μ.innerContent_bot (· ≤ ·) μ.innerContent_iSup_nat _ _).trans ?_
  simp only [μ.is_mul_left_invariant_innerContent h3, Finset.sum_const, nsmul_eq_mul, le_refl]

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

Goal state before:
pp: G : Type u_1
H : Type u_2
α : Type u_3
β : Type u_4
inst✝⁵ : Group G
inst✝⁴ : Group H
inst✝³ : MulAction G α
inst✝² : MeasurableSpace α
inst✝¹ : MulAction H β
inst✝ : MeasurableSpace β
s : Set α
μ : Measure α
ν : Measure β
h : IsFundamentalDomain G s μ
f : β → α
hf : QuasiMeasurePreserving f ν μ
a b : H
hab : a ≠ b
e : G ≃ H
hef : ∀ (g : G), Semiconj f (fun x ↦ e g • x) fun x ↦ g • x
⊢ (AEDisjoint ν on fun g ↦ g • f ⁻¹' s) a b

Tactic:
have : (e.symm a⁻¹)⁻¹ ≠ (e.symm b⁻¹)⁻¹ := by simp [hab]

Goal state after:
G : Type u_1
H : Type u_2
α : Type u_3
β : Type u_4
inst✝⁵ : Group G
inst✝⁴ : Group H
inst✝³ : MulAction G α
inst✝² : MeasurableSpace α
inst✝¹ : MulAction H β
inst✝ : MeasurableSpace β
s : Set α
μ : Measure α
ν : Measure β
h : IsFundamentalDomain G s μ
f : β → α
hf : QuasiMeasurePreserving f ν μ
a b : H
hab : a ≠ b
e : G ≃ H
hef : ∀ (g : G), Semiconj f (fun x ↦ e g • x) fun x ↦ g • x
this : (e.symm a⁻¹)⁻¹ ≠ (e.symm b⁻¹)⁻¹
⊢ (AEDisjoint ν on fun g ↦ g • f ⁻¹' s) a b
Module: Mathlib.MeasureTheory.Measure.Content

Goal state before:
pp: G : Type w
inst✝² : TopologicalSpace G
μ : Content G
inst✝¹ : R1Space G
S : MeasurableSpace G
inst✝ : BorelSpace G
U : Set G
hU : U ∈ {s | IsOpen s}
U' : Opens G
this : Nonempty { L // ↑L ⊆ ↑U' ∩ U }
L : Compacts G
hL : ↑L ⊆ ↑U' ∩ U
L' : Compacts G := { carrier := closure ↑L, isCompact' := ⋯ }
⊢ μ L + μ.outerMeasure (↑U' \ U) ≤ μ.outerMeasure ↑U'

Tactic:
show μ L ≤ μ L' from μ.mono _ _ subset_closure

Goal state after:
G : Type w
inst✝² : TopologicalSpace G
μ : Content G
inst✝¹ : R1Space G
S : MeasurableSpace G
inst✝ : BorelSpace G
U : Set G
hU : U ∈ {s | IsOpen s}
U' : Opens G
this : Nonempty { L // ↑L ⊆ ↑U' ∩ U }
L : Compacts G
hL : ↑L ⊆ ↑U' ∩ U
L' : Compacts G := { carrier := closure ↑L, isCompact' := ⋯ }
⊢ μ L' + μ.outerMeasure (↑U' \ U) ≤ μ.outerMeasure ↑U'
Module: Mathlib.MeasureTheory.Group.FundamentalDomain

Goal state before:
pp: G : Type u_1
α : Type u_3
inst✝⁴ : Group G
inst✝³ : MulAction G α
inst✝² : MeasurableSpace α
s : Set α
μ : Measure α
inst✝¹ : MeasurableConstSMul G α
inst✝ : SMulInvariantMeasure G α μ
h : IsFundamentalDomain G s μ
g g' : G
x : α
⊢ (MulAction.toPerm g)
      ((fun x ↦
          { toFun := fun g' ↦ g⁻¹ * g' * g, invFun := fun g' ↦ g * g' * g⁻¹, left_inv := ⋯, right_inv := ⋯ } g' • x)
        x) =
    (fun x ↦ g' • x) ((MulAction.toPerm g) x)

Tactic:
by simp [smul_smul, mul_assoc]

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

Goal state before:
pp: G : Type w
inst✝² : TopologicalSpace G
μ : Content G
inst✝¹ : R1Space G
S : MeasurableSpace G
inst✝ : BorelSpace G
⊢ μ.measure.OuterRegular

Tactic:
refine ⟨fun A hA r (hr : _ < _) ↦ ?_⟩

Goal state after:
G : Type w
inst✝² : TopologicalSpace G
μ : Content G
inst✝¹ : R1Space G
S : MeasurableSpace G
inst✝ : BorelSpace G
A : Set G
hA : MeasurableSet A
r : ℝ≥0∞
hr : μ.measure A < r
⊢ ∃ U ⊇ A, IsOpen U ∧ μ.measure U < r
Module: Mathlib.Analysis.InnerProductSpace.Defs

Goal state before:
pp: 𝕜 : Type u_1
F : Type u_3
inst✝² : RCLike 𝕜
inst✝¹ : AddCommGroup F
inst✝ : Module 𝕜 F
c : PreInnerProductSpace.Core 𝕜 F
⊢ normSq 0 = 0

Tactic:
simp [normSq, inner_self_of_eq_zero]

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: X : Type u_6
f : X → ℝ
m m0 : MeasurableSpace X
μ : Measure X
hm : m ≤ m0
g : SimpleFunc X ℝ
hf : Integrable f μ
⊢ Integrable (⇑g * f) μ

Tactic:
← SimpleFunc.coe_toLargerSpace_eq hm g

Goal state after:
X : Type u_6
f : X → ℝ
m m0 : MeasurableSpace X
μ : Measure X
hm : m ≤ m0
g : SimpleFunc X ℝ
hf : Integrable f μ
⊢ Integrable (⇑(SimpleFunc.toLargerSpace hm g) * f) μ
Module: Mathlib.Analysis.InnerProductSpace.Subspace

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝⁵ : RCLike 𝕜
inst✝⁴ : SeminormedAddCommGroup E
inst✝³ : InnerProductSpace 𝕜 E
ι : Type u_4
G : ι → Type u_5
inst✝² : (i : ι) → NormedAddCommGroup (G i)
inst✝¹ : (i : ι) → InnerProductSpace 𝕜 (G i)
V : (i : ι) → G i →ₗᵢ[𝕜] E
hV : OrthogonalFamily 𝕜 G V
inst✝ : DecidableEq ι
f : (i : ι) → G i
s₁ s₂ : Finset ι
⊢ ‖∑ i ∈ s₁, (V i) (f i) - ∑ i ∈ s₂, (V i) (f i)‖ ^ 2 = ∑ i ∈ s₁ \ s₂, ‖f i‖ ^ 2 + ∑ i ∈ s₂ \ s₁, ‖f i‖ ^ 2

Tactic:
← Finset.sum_sdiff_sub_sum_sdiff,

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝⁵ : RCLike 𝕜
inst✝⁴ : SeminormedAddCommGroup E
inst✝³ : InnerProductSpace 𝕜 E
ι : Type u_4
G : ι → Type u_5
inst✝² : (i : ι) → NormedAddCommGroup (G i)
inst✝¹ : (i : ι) → InnerProductSpace 𝕜 (G i)
V : (i : ι) → G i →ₗᵢ[𝕜] E
hV : OrthogonalFamily 𝕜 G V
inst✝ : DecidableEq ι
f : (i : ι) → G i
s₁ s₂ : Finset ι
⊢ ‖∑ x ∈ s₁ \ s₂, (V x) (f x) - ∑ x ∈ s₂ \ s₁, (V x) (f x)‖ ^ 2 = ∑ i ∈ s₁ \ s₂, ‖f i‖ ^ 2 + ∑ i ∈ s₂ \ s₁, ‖f i‖ ^ 2
Module: Mathlib.Analysis.InnerProductSpace.LinearMap

Goal state before:
pp: 𝕜 : Type u_4
inst✝⁴ : RCLike 𝕜
F : Type u_8
H : Type u_9
inst✝³ : NormedAddCommGroup F
inst✝² : InnerProductSpace 𝕜 F
inst✝¹ : NormedAddCommGroup H
inst✝ : InnerProductSpace 𝕜 H
a c : F
b d : H
ha : a ≠ 0
hb : b ≠ 0
h : ∀ (x : H), ⟪b, x⟫_𝕜 • a = ⟪d, x⟫_𝕜 • c
h₂ : ∀ (x : F), ⟪a, x⟫_𝕜 • b = ⟪c, x⟫_𝕜 • d
h₃ : a = (⟪d, b⟫_𝕜 / ⟪b, b⟫_𝕜) • c
h₄ : b = (⟪d, b⟫_𝕜 / ⟪b, b⟫_𝕜 * (⟪c, c⟫_𝕜 / ⟪a, a⟫_𝕜)) • d
h₅ : ⟪d, b⟫_𝕜 ≠ 0
h₆ : c ≠ 0
⊢ 0 < ‖c‖ ^ 2

Tactic:
by simpa [sq_pos_iff]

Goal state after:
Module: Mathlib.Analysis.InnerProductSpace.LinearMap

Goal state before:
pp: 𝕜 : Type u_4
inst✝⁴ : RCLike 𝕜
F : Type u_8
H : Type u_9
inst✝³ : NormedAddCommGroup F
inst✝² : InnerProductSpace 𝕜 F
inst✝¹ : NormedAddCommGroup H
inst✝ : InnerProductSpace 𝕜 H
a c : F
b d : H
ha : a ≠ 0
hb : b ≠ 0
h : ∀ (x : H), ⟪b, x⟫_𝕜 • a = ⟪d, x⟫_𝕜 • c
h₂ : ∀ (x : F), ⟪a, x⟫_𝕜 • b = ⟪c, x⟫_𝕜 • d
h₃ : a = (⟪d, b⟫_𝕜 / ⟪b, b⟫_𝕜) • c
h₄ : b = (⟪d, b⟫_𝕜 / ⟪b, b⟫_𝕜 * (⟪c, c⟫_𝕜 / ⟪a, a⟫_𝕜)) • d
h₅ : ⟪d, b⟫_𝕜 ≠ 0
h₆ : c ≠ 0
⊢ 0 < ‖a‖ ^ 2

Tactic:
by simpa [sq_pos_iff]

Goal state after:
Module: Mathlib.Analysis.InnerProductSpace.Subspace

Goal state before:
pp: case h
𝕜 : Type u_1
E : Type u_2
inst✝⁵ : RCLike 𝕜
inst✝⁴ : SeminormedAddCommGroup E
inst✝³ : InnerProductSpace 𝕜 E
ι : Type u_4
G : ι → Type u_5
inst✝² : (i : ι) → NormedAddCommGroup (G i)
inst✝¹ : (i : ι) → InnerProductSpace 𝕜 (G i)
V : (i : ι) → G i →ₗᵢ[𝕜] E
hV : OrthogonalFamily 𝕜 G V
inst✝ : CompleteSpace E
f : (i : ι) → G i
hf : ∀ ε > 0, ∃ N, ∀ (m : Finset ι), N ⊆ m → ∀ (n : Finset ι), N ⊆ n → |∑ i ∈ m, ‖f i‖ ^ 2 - ∑ i ∈ n, ‖f i‖ ^ 2| < ε
ε : ℝ
hε : ε > 0
hε' : 0 < ε ^ 2 / 2
a : Finset ι
H : ∀ (m : Finset ι), a ⊆ m → ∀ (n : Finset ι), a ⊆ n → |∑ i ∈ m, ‖f i‖ ^ 2 - ∑ i ∈ n, ‖f i‖ ^ 2| < ε ^ 2 / 2
s₁ : Finset ι
hs₁ : a ⊆ s₁
s₂ : Finset ι
hs₂ : a ⊆ s₂
⊢ ‖∑ i ∈ s₁, (V i) (f i) - ∑ i ∈ s₂, (V i) (f i)‖ < ε

Tactic:
refine (abs_lt_of_sq_lt_sq' ?_ (le_of_lt hε)).2

Goal state after:
case h
𝕜 : Type u_1
E : Type u_2
inst✝⁵ : RCLike 𝕜
inst✝⁴ : SeminormedAddCommGroup E
inst✝³ : InnerProductSpace 𝕜 E
ι : Type u_4
G : ι → Type u_5
inst✝² : (i : ι) → NormedAddCommGroup (G i)
inst✝¹ : (i : ι) → InnerProductSpace 𝕜 (G i)
V : (i : ι) → G i →ₗᵢ[𝕜] E
hV : OrthogonalFamily 𝕜 G V
inst✝ : CompleteSpace E
f : (i : ι) → G i
hf : ∀ ε > 0, ∃ N, ∀ (m : Finset ι), N ⊆ m → ∀ (n : Finset ι), N ⊆ n → |∑ i ∈ m, ‖f i‖ ^ 2 - ∑ i ∈ n, ‖f i‖ ^ 2| < ε
ε : ℝ
hε : ε > 0
hε' : 0 < ε ^ 2 / 2
a : Finset ι
H : ∀ (m : Finset ι), a ⊆ m → ∀ (n : Finset ι), a ⊆ n → |∑ i ∈ m, ‖f i‖ ^ 2 - ∑ i ∈ n, ‖f i‖ ^ 2| < ε ^ 2 / 2
s₁ : Finset ι
hs₁ : a ⊆ s₁
s₂ : Finset ι
hs₂ : a ⊆ s₂
⊢ ‖∑ i ∈ s₁, (V i) (f i) - ∑ i ∈ s₂, (V i) (f i)‖ ^ 2 < ε ^ 2
Module: Mathlib.Analysis.InnerProductSpace.Orthogonal

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
K : Submodule 𝕜 E
h : Kᗮ = ⊤
⊢ K = ⊥

Tactic:
have : K ⊓ Kᗮ = ⊥ := K.orthogonal_disjoint.eq_bot

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
K : Submodule 𝕜 E
h : Kᗮ = ⊤
this : K ⊓ Kᗮ = ⊥
⊢ K = ⊥
Module: Mathlib.Analysis.InnerProductSpace.Orthogonal

Goal state before:
pp: 𝕜 : Type u_4
E : Type u_5
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
K : ClosedSubmodule 𝕜 E
h : Kᗮ = ⊤
⊢ K = ⊥

Tactic:
have : K ⊓ Kᗮ = ⊥ := K.orthogonal_disjoint.eq_bot

Goal state after:
𝕜 : Type u_4
E : Type u_5
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
K : ClosedSubmodule 𝕜 E
h : Kᗮ = ⊤
this : K ⊓ Kᗮ = ⊥
⊢ K = ⊥
Module: Mathlib.Analysis.InnerProductSpace.Symmetric

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
T : E →ₗ[𝕜] E
hT : T.IsSymmetric
h : ∀ (x : E), ⟪T x, x⟫ = 0
x : E
⊢ T x = 0

Tactic:
rw [← @inner_self_eq_zero 𝕜, hT.inner_map_polarization]

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
T : E →ₗ[𝕜] E
hT : T.IsSymmetric
h : ∀ (x : E), ⟪T x, x⟫ = 0
x : E
⊢ (⟪T (x + T x), x + T x⟫ - ⟪T (x - T x), x - T x⟫ - I * ⟪T (x + I • T x), x + I • T x⟫ +
        I * ⟪T (x - I • T x), x - I • T x⟫) /
      4 =
    0
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x✝ : E
⊢ ⊤.starProjection x✝ = (ContinuousLinearMap.id 𝕜 E) x✝

Tactic:
exact starProjection_eq_self_iff.mpr trivial

Goal state after:
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : InnerProductSpace 𝕜 E
U V : Submodule 𝕜 E
inst✝ : U.HasOrthogonalProjection
h : U ⟂ V
v : ↥V
⊢ ↑((U.orthogonalProjectionOnto ∘SL V.subtypeL) v) = ↑(0 v)

Tactic:
simp [orthogonalProjectionOnto_apply_of_mem_orthogonal <| h.symm v.prop]

Goal state after:
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : InnerProductSpace 𝕜 E
U V : Submodule 𝕜 E
inst✝¹ : U.HasOrthogonalProjection
inst✝ : V.HasOrthogonalProjection
h : U ⟂ V
⊢ U.subtypeL ∘SL (U.orthogonalProjectionOnto ∘SL V.subtypeL) ∘SL V.orthogonalProjectionOnto = 0

Tactic:
simp [h.orthogonalProjectionOnto_comp_subtypeL]

Goal state after:
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : InnerProductSpace 𝕜 E
U V : Submodule 𝕜 E
inst✝¹ : U.HasOrthogonalProjection
inst✝ : V.HasOrthogonalProjection
⊢ U.starProjection ∘SL V.starProjection = 0 ↔ U ⟂ V

Tactic:
refine ⟨fun h => ?_, fun h => h.starProjection_comp_starProjection⟩
  rw [← orthogonalProjectionOnto_comp_subtypeL_eq_zero_iff]
  simp only [ContinuousLinearMap.ext_iff, ContinuousLinearMap.comp_apply, subtypeL_apply,
    starProjection_apply, zero_apply, coe_eq_zero] at h ⊢
  intro x
  simpa using h (x : E)

Goal state after:
Module: Mathlib.Analysis.Normed.Lp.ProdLp

Goal state before:
pp: p : ℝ≥0∞
𝕜 : Type u_1
α : Type u_2
β : Type u_3
hp✝ : Fact (1 ≤ p)
inst✝¹ : PseudoEMetricSpace α
inst✝ : PseudoEMetricSpace β
f g h : WithLp p (α × β)
hp : 1 ≤ p.toReal
⊢ ((edist f.fst g.fst + edist g.fst h.fst) ^ p.toReal + (edist f.snd g.snd + edist g.snd h.snd) ^ p.toReal) ^
      (1 / p.toReal) ≤
    (edist f.fst g.fst ^ p.toReal + edist f.snd g.snd ^ p.toReal) ^ (1 / p.toReal) +
      (edist g.fst h.fst ^ p.toReal + edist g.snd h.snd ^ p.toReal) ^ (1 / p.toReal)

Tactic:
by
          have := ENNReal.Lp_add_le {0, 1}
            (if · = 0 then edist f.fst g.fst else edist f.snd g.snd)
            (if · = 0 then edist g.fst h.fst else edist g.snd h.snd) hp
          simp only [Finset.mem_singleton, not_false_eq_true, Finset.sum_insert,
            Finset.sum_singleton, reduceCtorEq] at this
          exact this

Goal state after:
Module: Mathlib.Analysis.Normed.Lp.ProdLp

Goal state before:
pp: p : ℝ≥0∞
α : Type u_2
β : Type u_3
hp : Fact (1 ≤ p)
inst✝¹ : PseudoEMetricSpace α
inst✝ : PseudoEMetricSpace β
x y : WithLp p (α × β)
h : 1 ≤ p.toReal
cancel : p.toReal * (1 / p.toReal) = 1
⊢ (edist x.fst y.fst ^ p.toReal) ^ (1 / p.toReal) ≤
    (edist x.fst y.fst ^ p.toReal + edist x.snd y.snd ^ p.toReal) ^ (1 / p.toReal)

Tactic:
by
          gcongr
          simp only [self_le_add_right]

Goal state after: