mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Measure.Stieltjes

Goal state before:
pp: R : Type u_1
inst✝⁶ : LinearOrder R
inst✝⁵ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁴ : OrderTopology R
inst✝³ : CompactIccSpace R
inst✝² : MeasurableSpace R
inst✝¹ : BorelSpace R
inst✝ : DenselyOrdered R
s : Set R
t : ℕ → Set R
ht : s ⊆ ⋃ i, t i
ε : ℝ≥0
ε0 : 0 < ε
h : ∑' (i : ℕ), f.length (t i) < ∞
⊢ ⨅ t, ⨅ (_ : s ⊆ t), ⨅ (_ : MeasurableSet t), f.outer t ≤ ∑' (i : ℕ), f.length (t i) + ↑ε

Tactic:
rcases ENNReal.exists_pos_sum_of_countable (ENNReal.coe_pos.2 ε0).ne' ℕ with ⟨ε', ε'0, hε⟩

Goal state after:
R : Type u_1
inst✝⁶ : LinearOrder R
inst✝⁵ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁴ : OrderTopology R
inst✝³ : CompactIccSpace R
inst✝² : MeasurableSpace R
inst✝¹ : BorelSpace R
inst✝ : DenselyOrdered R
s : Set R
t : ℕ → Set R
ht : s ⊆ ⋃ i, t i
ε : ℝ≥0
ε0 : 0 < ε
h : ∑' (i : ℕ), f.length (t i) < ∞
ε' : ℕ → ℝ≥0
ε'0 : ∀ (i : ℕ), 0 < ε' i
hε : ∑' (i : ℕ), ↑(ε' i) < ↑ε
⊢ ⨅ t, ⨅ (_ : s ⊆ t), ⨅ (_ : MeasurableSet t), f.outer t ≤ ∑' (i : ℕ), f.length (t i) + ↑ε
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: X : Type u_1
E : Type u_3
mX : MeasurableSpace X
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : X → E
s t : Set X
μ : Measure X
ht : NullMeasurableSet t μ
hts : s ⊆ t
h't : ∀ᵐ (x : X) ∂μ, x ∈ t \ s → f x = 0
h : IntegrableOn f t μ
f' : X → E := ⋯
⊢ ∀ᵐ (x : X) ∂μ, x ∈ t \ s → AEStronglyMeasurable.mk f ⋯ x = 0

Tactic:
filter_upwards [h't, ae_imp_of_ae_restrict h.1.ae_eq_mk] with x hx h'x h''x

Goal state after:
X : Type u_1
E : Type u_3
mX : MeasurableSpace X
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : X → E
s t : Set X
μ : Measure X
ht : NullMeasurableSet t μ
hts : s ⊆ t
h't : ∀ᵐ (x : X) ∂μ, x ∈ t \ s → f x = 0
h : IntegrableOn f t μ
f' : X → E := AEStronglyMeasurable.mk f ⋯
x : X
hx : x ∈ t \ s → f x = 0
h'x : x ∈ t → f x = AEStronglyMeasurable.mk f ⋯ x
h''x : x ∈ t \ s
⊢ AEStronglyMeasurable.mk f ⋯ x = 0
Module: Mathlib.MeasureTheory.Measure.Haar.Basic

Goal state before:
pp: G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₀ : PositiveCompacts G
K : Compacts G
V : Set G
hV : (interior V).Nonempty
s : Finset G
h1s : ↑K ⊆ ⋃ g ∈ s, (fun h ↦ g * h) ⁻¹' ↑K₀
h2s : s.card = index ↑K ↑K₀
t : Finset G
h1t : ↑K₀ ⊆ ⋃ g ∈ t, (fun h ↦ g * h) ⁻¹' V
h2t : t.card = index (↑K₀) V
⊢ index (↑K) V ≤ t.card * s.card

Tactic:
refine le_trans ?_ Finset.card_mul_le

Goal state after:
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₀ : PositiveCompacts G
K : Compacts G
V : Set G
hV : (interior V).Nonempty
s : Finset G
h1s : ↑K ⊆ ⋃ g ∈ s, (fun h ↦ g * h) ⁻¹' ↑K₀
h2s : s.card = index ↑K ↑K₀
t : Finset G
h1t : ↑K₀ ⊆ ⋃ g ∈ t, (fun h ↦ g * h) ⁻¹' V
h2t : t.card = index (↑K₀) V
⊢ index (↑K) V ≤ (t * s).card
Module: Mathlib.MeasureTheory.Measure.Haar.Basic

Goal state before:
pp: G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K : PositiveCompacts G
V : Set G
hV : (interior V).Nonempty
t : Finset G
h1t : t ∈ {t | ↑K ⊆ ⋃ g ∈ t, (fun h ↦ g * h) ⁻¹' V}
h2t : t.card = 0
⊢ False

Tactic:
rw [Finset.card_eq_zero] at h2t

Goal state after:
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K : PositiveCompacts G
V : Set G
hV : (interior V).Nonempty
t : Finset G
h1t : t ∈ {t | ↑K ⊆ ⋃ g ∈ t, (fun h ↦ g * h) ⁻¹' V}
h2t : t = ∅
⊢ False
Module: Mathlib.MeasureTheory.Measure.Stieltjes

Goal state before:
pp: case inl
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
a b : R
hab : b ≤ a
⊢ ofReal (leftLim (↑f) b - ↑f a) = 0

Tactic:
simp [ENNReal.ofReal_eq_zero, f.mono.leftLim_le hab]

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

Goal state before:
pp: case inl
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
x : R
this✝ : Nonempty R
val✝ : OrderBot R
hf : Tendsto (↑f) (pure ⊥) (𝓝 l)
this : Iic x = Icc ⊥ x
⊢ f.measure (Iic x) = ofReal (↑f x - l)

Tactic:
this,

Goal state after:
case inl
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
x : R
this✝ : Nonempty R
val✝ : OrderBot R
hf : Tendsto (↑f) (pure ⊥) (𝓝 l)
this : Iic x = Icc ⊥ x
⊢ f.measure (Icc ⊥ x) = ofReal (↑f x - l)
Module: Mathlib.MeasureTheory.Group.FundamentalDomain

Goal state before:
pp: case refine_1
G : Type u_1
α : Type u_3
inst✝⁶ : Group G
inst✝⁵ : MulAction G α
inst✝⁴ : MeasurableSpace α
ν : Measure α
inst✝³ : SMulInvariantMeasure G α ν
inst✝² : Countable G
inst✝¹ : MeasurableConstSMul G α
i : SigmaFinite ν
μ : Measure (Quotient α_mod_G)
inst✝ : QuotientMeasureEqMeasurePreimage ν μ
A : ℕ → Set α
hA_meas : ∀ (i : ℕ), MeasurableSet (A i)
hA : ∀ (i : ℕ), ν (A i) < ∞
hA' : ⋃ i, A i = univ
n : ℕ
s : Set α
fund_dom_s : IsFundamentalDomain G s ν
this : Quotient.mk α_mod_G ⁻¹' Quotient.mk α_mod_G '' A n = ⋃ g, (fun x ↦ g • x) '' A n
measπAn : MeasurableSet (Quotient.mk α_mod_G '' A n)
⊢ ν (Quotient.mk α_mod_G ⁻¹' Quotient.mk α_mod_G '' A n ∩ s) < ∞

Tactic:
this,

Goal state after:
case refine_1
G : Type u_1
α : Type u_3
inst✝⁶ : Group G
inst✝⁵ : MulAction G α
inst✝⁴ : MeasurableSpace α
ν : Measure α
inst✝³ : SMulInvariantMeasure G α ν
inst✝² : Countable G
inst✝¹ : MeasurableConstSMul G α
i : SigmaFinite ν
μ : Measure (Quotient α_mod_G)
inst✝ : QuotientMeasureEqMeasurePreimage ν μ
A : ℕ → Set α
hA_meas : ∀ (i : ℕ), MeasurableSet (A i)
hA : ∀ (i : ℕ), ν (A i) < ∞
hA' : ⋃ i, A i = univ
n : ℕ
s : Set α
fund_dom_s : IsFundamentalDomain G s ν
this : Quotient.mk α_mod_G ⁻¹' Quotient.mk α_mod_G '' A n = ⋃ g, (fun x ↦ g • x) '' A n
measπAn : MeasurableSet (Quotient.mk α_mod_G '' A n)
⊢ ν ((⋃ g, (fun x ↦ g • x) '' A n) ∩ s) < ∞
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: X : Type u_1
E : Type u_3
mX : MeasurableSpace X
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
f : X → E
μ : Measure X
inst✝¹ : PartialOrder X
x y : X
inst✝ : NullSingletonClass μ
⊢ ∫ (t : X) in Ico x y, f t ∂μ = ∫ (t : X) in Ioc x y, f t ∂μ

Tactic:
rw [integral_Ico_eq_integral_Ioo, integral_Ioc_eq_integral_Ioo]

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

Goal state before:
pp: case inl
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
x : R
this✝ : Nonempty R
val✝ : OrderTop R
hf : Tendsto (↑f) (pure ⊤) (𝓝 l)
this : Ici x = Icc x ⊤
⊢ f.measure (Ici x) = ofReal (l - leftLim (↑f) x)

Tactic:
this,

Goal state after:
case inl
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
x : R
this✝ : Nonempty R
val✝ : OrderTop R
hf : Tendsto (↑f) (pure ⊤) (𝓝 l)
this : Ici x = Icc x ⊤
⊢ f.measure (Icc x ⊤) = ofReal (l - leftLim (↑f) x)
Module: Mathlib.MeasureTheory.Group.FundamentalDomain

Goal state before:
pp: G : Type u_1
α : Type u_3
inst✝⁶ : Group G
inst✝⁵ : MulAction G α
inst✝⁴ : MeasurableSpace α
ν : Measure α
inst✝³ : SMulInvariantMeasure G α ν
inst✝² : Countable G
inst✝¹ : MeasurableConstSMul G α
μ : Measure (Quotient α_mod_G)
inst✝ : QuotientMeasureEqMeasurePreimage ν μ
hasFun : HasFundamentalDomain G α ν
h : covolume G α ν ≠ ∞
𝓕 : Set α
h𝓕 : IsFundamentalDomain G 𝓕 ν
⊢ ν 𝓕 < ∞

Tactic:
convert! Ne.lt_top h

Goal state after:
G : Type u_1
α : Type u_3
inst✝⁶ : Group G
inst✝⁵ : MulAction G α
inst✝⁴ : MeasurableSpace α
ν : Measure α
inst✝³ : SMulInvariantMeasure G α ν
inst✝² : Countable G
inst✝¹ : MeasurableConstSMul G α
μ : Measure (Quotient α_mod_G)
inst✝ : QuotientMeasureEqMeasurePreimage ν μ
hasFun : HasFundamentalDomain G α ν
h : covolume G α ν ≠ ∞
𝓕 : Set α
h𝓕 : IsFundamentalDomain G 𝓕 ν
⊢ ν 𝓕 = covolume G α ν
Module: Mathlib.MeasureTheory.Measure.Stieltjes

Goal state before:
pp: R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
hf : Tendsto (↑f) atTop (𝓝 l)
x : R
⊢ f.measure (Ioi x) = ofReal (l - ↑f x)

Tactic:
rw [← Ici_sdiff_left, measure_sdiff _ (nullMeasurableSet_singleton x), measure_singleton,
    f.measure_Ici hf, ← ofReal_sub _ (sub_nonneg.mpr <| Monotone.leftLim_le f.mono' le_rfl)]

Goal state after:
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
hf : Tendsto (↑f) atTop (𝓝 l)
x : R
⊢ ofReal (l - leftLim (↑f) x - (↑f x - leftLim (↑f) x)) = ofReal (l - ↑f x)

R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
hf : Tendsto (↑f) atTop (𝓝 l)
x : R
⊢ f.measure {x} ≠ ∞

R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
f : StieltjesFunction R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
l : ℝ
hf : Tendsto (↑f) atTop (𝓝 l)
x : R
⊢ {x} ⊆ Ici x
Module: Mathlib.MeasureTheory.Measure.Haar.Basic

Goal state before:
pp: G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₀ : PositiveCompacts G
⊢ IsCompact (haarProduct ↑K₀)

Tactic:
apply isCompact_univ_pi

Goal state after:
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₀ : PositiveCompacts G
⊢ ∀ (i : Compacts G), IsCompact (Icc 0 ↑(index ↑i ↑K₀))
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
x y : F
⊢ ⟪-x, y⟫ = -⟪x, y⟫

Tactic:
by
  rw [← neg_one_smul 𝕜 x, inner_smul_left]
  simp

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

Goal state before:
pp: case pos.refine_2
X : Type u_1
mX : MeasurableSpace X
μ : Measure X
f : X → ℝ
s : Set X
g : X → ℝ
hf : ∀ x ∈ s, 0 ≤ f x
h : ∀ x ∈ s, f x ≤ g x
hg : IntegrableOn g s μ
h'f : AEStronglyMeasurable f (μ.restrict s)
⊢ f ≤ᵐ[μ.restrict s] g

Tactic:
· apply (ae_restrict_iff₀ ?_).2
    · filter_upwards with x hx using h x hx
    · exact nullMeasurableSet_le h'f.aemeasurable hg.aemeasurable

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

Goal state before:
pp: R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
c : ℝ≥0
f : StieltjesFunction R
a b : R
h : a ≤ b
this : leftLim (↑(c • f)) a = ↑c * leftLim (↑f) a
⊢ ofReal (↑c * ↑f b - leftLim (↑(c • f)) a) = c • ofReal (↑f b - leftLim (↑f) a)

Tactic:
this,

Goal state after:
R : Type u_1
inst✝⁷ : LinearOrder R
inst✝⁶ : TopologicalSpace R
inst✝⁵ : OrderTopology R
inst✝⁴ : CompactIccSpace R
inst✝³ : MeasurableSpace R
inst✝² : BorelSpace R
inst✝¹ : SecondCountableTopology R
inst✝ : DenselyOrdered R
c : ℝ≥0
f : StieltjesFunction R
a b : R
h : a ≤ b
this : leftLim (↑(c • f)) a = ↑c * leftLim (↑f) a
⊢ ofReal (↑c * ↑f b - ↑c * leftLim (↑f) a) = c • ofReal (↑f b - leftLim (↑f) a)
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: X : Type u_6
f : X → ℝ
m0 : MeasurableSpace X
μ : Measure X
g : SimpleFunc X ℝ
hf : Integrable f μ
c : ℝ
s : Set X
hs : MeasurableSet s
this : s.indicator (const X c) * f = s.indicator (c • f)
⊢ Integrable (s.indicator (const X c) * f) μ

Tactic:
this,

Goal state after:
X : Type u_6
f : X → ℝ
m0 : MeasurableSpace X
μ : Measure X
g : SimpleFunc X ℝ
hf : Integrable f μ
c : ℝ
s : Set X
hs : MeasurableSet s
this : s.indicator (const X c) * f = s.indicator (c • f)
⊢ Integrable (s.indicator (c • f)) μ
Module: Mathlib.Analysis.InnerProductSpace.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x y : E
⊢ ⟪-x, y⟫ = -⟪x, y⟫

Tactic:
by
  rw [← neg_one_smul 𝕜 x, inner_smul_left]
  simp

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

Goal state before:
pp: F : Type u_3
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
K : Set F
ne : K.Nonempty
h₁ : IsComplete K
h₂ : Convex ℝ K
u : F
δ : ℝ := ⨅ w, ‖u - ↑w‖
this : Nonempty ↑K := Set.Nonempty.to_subtype ne
zero_le_δ : 0 ≤ δ
δ_le : ∀ (w : ↑K), δ ≤ ‖u - ↑w‖
δ_le' : ∀ w ∈ K, δ ≤ ‖u - w‖
w : ℕ → ↑K
hw : ∀ (n : ℕ), ‖u - ↑(w n)‖ < δ + 1 / (↑n + 1)
h : Tendsto (fun x ↦ δ) atTop (𝓝 δ)
⊢ δ = δ + 0

Tactic:
simp only [add_zero]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Haar.Basic

Goal state before:
pp: G : Type u_1
inst✝⁷ : Group G
inst✝⁶ : TopologicalSpace G
inst✝⁵ : IsTopologicalGroup G
inst✝⁴ : MeasurableSpace G
inst✝³ : BorelSpace G
inst✝² : SecondCountableTopology G
μ : Measure G
inst✝¹ : SigmaFinite μ
inst✝ : μ.IsMulLeftInvariant
K : Set G
hK : IsCompact K
h2K : (interior K).Nonempty
hμK : μ K ≠ ∞
⊢ μ.Regular

Tactic:
haarMeasure_unique μ ⟨⟨K, hK⟩, h2K⟩

Goal state after:
G : Type u_1
inst✝⁷ : Group G
inst✝⁶ : TopologicalSpace G
inst✝⁵ : IsTopologicalGroup G
inst✝⁴ : MeasurableSpace G
inst✝³ : BorelSpace G
inst✝² : SecondCountableTopology G
μ : Measure G
inst✝¹ : SigmaFinite μ
inst✝ : μ.IsMulLeftInvariant
K : Set G
hK : IsCompact K
h2K : (interior K).Nonempty
hμK : μ K ≠ ∞
⊢ (μ ↑{ carrier := K, isCompact' := hK, interior_nonempty' := h2K } •
      haarMeasure { carrier := K, isCompact' := hK, interior_nonempty' := h2K }).Regular
Module: Mathlib.Analysis.InnerProductSpace.Projection.Minimal

Goal state before:
pp: F : Type u_3
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
K : Set F
h✝ : Convex ℝ K
u v : F
hv : v ∈ K
this✝¹ : Nonempty ↑K := Nonempty.intro ⟨v, hv⟩
h : ∀ w ∈ K, ⟪u - v, w - v⟫_ℝ ≤ 0
w : ↑K
this✝ : ⟪u - v, ↑w - v⟫_ℝ ≤ 0
this : u - v - (↑w - v) = u - ↑w
⊢ ‖u - v - (↑w - v)‖ ^ 2 = ‖u - ↑w‖ * ‖u - ↑w‖

Tactic:
this,

Goal state after:
F : Type u_3
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
K : Set F
h✝ : Convex ℝ K
u v : F
hv : v ∈ K
this✝¹ : Nonempty ↑K := Nonempty.intro ⟨v, hv⟩
h : ∀ w ∈ K, ⟪u - v, w - v⟫_ℝ ≤ 0
w : ↑K
this✝ : ⟪u - v, ↑w - v⟫_ℝ ≤ 0
this : u - v - (↑w - v) = u - ↑w
⊢ ‖u - ↑w‖ ^ 2 = ‖u - ↑w‖ * ‖u - ↑w‖
Module: Mathlib.Analysis.InnerProductSpace.Orthonormal

Goal state before:
pp: case refine_1.refine_1
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
s : Set E
hs : Orthonormal 𝕜 Subtype.val
c : Set (Set E)
hc : c ⊆ {b | Orthonormal 𝕜 Subtype.val}
cc : IsChain (fun x1 x2 ↦ x1 ⊆ x2) c
_c0 : c.Nonempty
⊢ ⋃₀ c ∈ {b | Orthonormal 𝕜 Subtype.val}

Tactic:
exact orthonormal_sUnion_of_directed cc.directedOn fun x xc => hc xc

Goal state after:
Module: Mathlib.Topology.Baire.CompleteMetrizable

Goal state before:
pp: case refine_3
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : IsCompletelyPseudoMetrizableSpace X
x✝ : UpgradedIsCompletelyPseudoMetrizableSpace X := upgradeIsCompletelyPseudoMetrizable X
f : ℕ → Set X
ho : ∀ (n : ℕ), IsOpen (f n)
hd : ∀ (n : ℕ), Dense (f n)
B : ℕ → ℝ≥0∞ := fun n ↦ 1 / 2 ^ n
Bpos : ∀ (n : ℕ), 0 < B n
n : ℕ
x : X
δ : ℝ≥0∞
δpos : δ ≠ 0
this : x ∈ closure (f n)
y : X
ys : y ∈ f n
xy : edist y x < δ / 2
r : ℝ≥0∞
rpos : r > 0
hr : closedEBall y r ⊆ f n
z : X
hz : z ∈ closedEBall y (min (min (δ / 2) r) (B (n + 1)))
⊢ z ∈ closedEBall x δ

Tactic:
show z ∈ closedEBall x δ

Goal state after:
case refine_3
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : IsCompletelyPseudoMetrizableSpace X
x✝ : UpgradedIsCompletelyPseudoMetrizableSpace X := upgradeIsCompletelyPseudoMetrizable X
f : ℕ → Set X
ho : ∀ (n : ℕ), IsOpen (f n)
hd : ∀ (n : ℕ), Dense (f n)
B : ℕ → ℝ≥0∞ := fun n ↦ 1 / 2 ^ n
Bpos : ∀ (n : ℕ), 0 < B n
n : ℕ
x : X
δ : ℝ≥0∞
δpos : δ ≠ 0
this : x ∈ closure (f n)
y : X
ys : y ∈ f n
xy : edist y x < δ / 2
r : ℝ≥0∞
rpos : r > 0
hr : closedEBall y r ⊆ f n
z : X
hz : z ∈ closedEBall y (min (min (δ / 2) r) (B (n + 1)))
⊢ z ∈ closedEBall x δ
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
v : E
⊢ v ∈ Kᗮ ↔ ∀ u ∈ K, ⟪v, u⟫ = 0

Tactic:
by
  simp_rw [mem_orthogonal, inner_eq_zero_symm]

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

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 : InnerProductSpace 𝕜 E
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace 𝕜 F
K : Submodule 𝕜 E
f : E ≃ₗᵢ[𝕜] F
this : f.toLinearIsometry.range = ⊤
⊢ (map f.toLinearIsometry.toLinearMap K)ᗮ ⊓ f.toLinearIsometry.range = (map (↑f.toLinearEquiv) K)ᗮ

Tactic:
this,

Goal state after:
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : InnerProductSpace 𝕜 E
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace 𝕜 F
K : Submodule 𝕜 E
f : E ≃ₗᵢ[𝕜] F
this : f.toLinearIsometry.range = ⊤
⊢ (map f.toLinearIsometry.toLinearMap K)ᗮ ⊓ ⊤ = (map (↑f.toLinearEquiv) K)ᗮ
Module: Mathlib.Analysis.InnerProductSpace.Projection.Submodule

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
K : Submodule 𝕜 E
inst✝ : K.HasOrthogonalProjection
h : K = ⊤
⊢ Kᗮ = ⊥

Tactic:
by rw [h, Submodule.top_orthogonal_eq_bot]

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

Goal state before:
pp: case pos
𝕜 : Type u_1
E : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : InnerProductSpace 𝕜 E
K : Submodule 𝕜 E
inst✝ : FiniteDimensional 𝕜 ↥K
hK : FiniteDimensional 𝕜 ↥Kᗮ
e : (↥K × ↥Kᗮ) ≃ₗ[𝕜] E := K.prodEquivOfIsCompl Kᗮ ⋯
b : Basis (Fin (finrank 𝕜 ↥K) ⊕ Fin (finrank 𝕜 ↥Kᗮ)) 𝕜 (↥K × ↥Kᗮ) := (finBasis 𝕜 ↥K).prod (finBasis 𝕜 ↥Kᗮ)
this : (LinearMap.toMatrix b b) (↑e.symm ∘ₗ ↑K.reflection.toLinearEquiv ∘ₗ ↑e.symm.symm) = Matrix.fromBlocks 1 0 0 (-1)
⊢ ((LinearMap.toMatrix b b) (↑e.symm ∘ₗ ↑K.reflection.toLinearEquiv ∘ₗ ↑e.symm.symm)).det = (-1) ^ finrank 𝕜 ↥Kᗮ

Tactic:
this,

Goal state after:
case pos
𝕜 : Type u_1
E : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : InnerProductSpace 𝕜 E
K : Submodule 𝕜 E
inst✝ : FiniteDimensional 𝕜 ↥K
hK : FiniteDimensional 𝕜 ↥Kᗮ
e : (↥K × ↥Kᗮ) ≃ₗ[𝕜] E := K.prodEquivOfIsCompl Kᗮ ⋯
b : Basis (Fin (finrank 𝕜 ↥K) ⊕ Fin (finrank 𝕜 ↥Kᗮ)) 𝕜 (↥K × ↥Kᗮ) := (finBasis 𝕜 ↥K).prod (finBasis 𝕜 ↥Kᗮ)
this : (LinearMap.toMatrix b b) (↑e.symm ∘ₗ ↑K.reflection.toLinearEquiv ∘ₗ ↑e.symm.symm) = Matrix.fromBlocks 1 0 0 (-1)
⊢ (Matrix.fromBlocks 1 0 0 (-1)).det = (-1) ^ finrank 𝕜 ↥Kᗮ
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.orthogonalProjectionOnto ∘SL V.subtypeL = 0
u : E
hu : u ∈ U
v : E
hv : v ∈ V
this : U.orthogonalProjectionOnto v = 0
⊢ v = v - ↑(U.orthogonalProjectionOnto v)

Tactic:
this,

Goal state after:
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.orthogonalProjectionOnto ∘SL V.subtypeL = 0
u : E
hu : u ∈ U
v : E
hv : v ∈ V
this : U.orthogonalProjectionOnto v = 0
⊢ v = v - ↑0
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
K : Submodule 𝕜 E
inst✝ : K.HasOrthogonalProjection
u : ↥K
v : E
⊢ ⟪K.starProjection v, ↑u⟫ + ⟪v - K.starProjection v, ↑u⟫ = ⟪v, ↑u⟫

Tactic:
rw [← inner_add_left, add_sub_cancel]

Goal state after:
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
p : E →ₗ[𝕜] E
hp : p.IsSymmetricProjection
this : p.range.HasOrthogonalProjection
⊢ ∃ (x : p.range.HasOrthogonalProjection), p = ↑p.range.starProjection

Tactic:
refine ⟨this, Eq.symm ?_⟩

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
p : E →ₗ[𝕜] E
hp : p.IsSymmetricProjection
this : p.range.HasOrthogonalProjection
⊢ ↑p.range.starProjection = p
Module: Mathlib.Analysis.InnerProductSpace.Projection.FiniteDimensional

Goal state before:
pp: case neg
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : InnerProductSpace ℝ F
inst✝ : FiniteDimensional ℝ F
n : ℕ
IH :
  ∀ (φ : F ≃ₗᵢ[ℝ] F),
    finrank ℝ ↥(↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).kerᗮ ≤ n →
      ∃ l, l.length ≤ n ∧ φ = (List.map (fun v ↦ (ℝ ∙ v)ᗮ.reflection) l).prod
φ : F ≃ₗᵢ[ℝ] F
hn : finrank ℝ ↥(↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).kerᗮ ≤ n + 1
W : Submodule ℝ F := (↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).ker
hW : ∀ w ∈ W, φ w = w
hn' : ¬finrank ℝ ↥Wᗮ ≤ n
this✝ : Nontrivial ↥Wᗮ
v : ↥Wᗮ
hv : v ≠ 0
hφv : φ ↑v ∈ Wᗮ
hv' : ↑v ∉ W
x : F := ↑v - φ ↑v
ρ : F ≃ₗᵢ[ℝ] F := (ℝ ∙ x)ᗮ.reflection
V : Submodule ℝ F := (↑(ContinuousLinearMap.id ℝ F - ↑↑(φ.trans ρ))).ker
hV : ∀ (w : F), ρ (φ w) = w → w ∈ V
H₂V : W ≤ V
H₁V : ↑v ∈ V
this : finrank ℝ ↥Vᗮ ≤ n
l : List F
hl : l.length ≤ n
hφl : ρ * φ = (List.map (fun v ↦ (ℝ ∙ v)ᗮ.reflection) l).prod
⊢ ∃ l, l.length ≤ n + 1 ∧ φ = (List.map (fun v ↦ (ℝ ∙ v)ᗮ.reflection) l).prod

Tactic:
refine ⟨x::l, Nat.succ_le_succ hl, ?_⟩

Goal state after:
case neg
F : Type u_3
inst✝² : NormedAddCommGroup F
inst✝¹ : InnerProductSpace ℝ F
inst✝ : FiniteDimensional ℝ F
n : ℕ
IH :
  ∀ (φ : F ≃ₗᵢ[ℝ] F),
    finrank ℝ ↥(↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).kerᗮ ≤ n →
      ∃ l, l.length ≤ n ∧ φ = (List.map (fun v ↦ (ℝ ∙ v)ᗮ.reflection) l).prod
φ : F ≃ₗᵢ[ℝ] F
hn : finrank ℝ ↥(↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).kerᗮ ≤ n + 1
W : Submodule ℝ F := (↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).ker
hW : ∀ w ∈ W, φ w = w
hn' : ¬finrank ℝ ↥Wᗮ ≤ n
this✝ : Nontrivial ↥Wᗮ
v : ↥Wᗮ
hv : v ≠ 0
hφv : φ ↑v ∈ Wᗮ
hv' : ↑v ∉ W
x : F := ↑v - φ ↑v
ρ : F ≃ₗᵢ[ℝ] F := (ℝ ∙ x)ᗮ.reflection
V : Submodule ℝ F := (↑(ContinuousLinearMap.id ℝ F - ↑↑(φ.trans ρ))).ker
hV : ∀ (w : F), ρ (φ w) = w → w ∈ V
H₂V : W ≤ V
H₁V : ↑v ∈ V
this : finrank ℝ ↥Vᗮ ≤ n
l : List F
hl : l.length ≤ n
hφl : ρ * φ = (List.map (fun v ↦ (ℝ ∙ v)ᗮ.reflection) l).prod
⊢ φ = (List.map (fun v ↦ (ℝ ∙ v)ᗮ.reflection) (x :: l)).prod