mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Group.FundamentalDomain

Goal state before:
pp: G : Type u_1
H : Type u_2
α : Type u_3
inst✝⁴ : Group G
inst✝³ : MulAction G α
s : Set α
inst✝² : Group H
inst✝¹ : MulAction H α
inst✝ : SMulCommClass H G α
g : H
⊢ g • s ∩ ⋃ g_1, ⋃ (_ : g_1 ≠ 1), g_1 • g • s = g • s ∩ g • ⋃ g, ⋃ (_ : g ≠ 1), g • s

Tactic:
smul_set_iUnion,

Goal state after:
G : Type u_1
H : Type u_2
α : Type u_3
inst✝⁴ : Group G
inst✝³ : MulAction G α
s : Set α
inst✝² : Group H
inst✝¹ : MulAction H α
inst✝ : SMulCommClass H G α
g : H
⊢ g • s ∩ ⋃ g_1, ⋃ (_ : g_1 ≠ 1), g_1 • g • s = g • s ∩ ⋃ i, ⋃ (_ : i ≠ 1), g • i • s
Module: Mathlib.MeasureTheory.Group.FundamentalDomain

Goal state before:
pp: G : Type u_1
H : Type u_2
α : Type u_3
inst✝⁴ : Group G
inst✝³ : MulAction G α
s : Set α
inst✝² : Group H
inst✝¹ : MulAction H α
inst✝ : SMulCommClass H G α
g : H
⊢ g • s \ ⋃ g_1, ⋃ (_ : g_1 ≠ 1), g_1 • g • s = g • s \ g • ⋃ g, ⋃ (_ : g ≠ 1), g • s

Tactic:
smul_set_iUnion,

Goal state after:
G : Type u_1
H : Type u_2
α : Type u_3
inst✝⁴ : Group G
inst✝³ : MulAction G α
s : Set α
inst✝² : Group H
inst✝¹ : MulAction H α
inst✝ : SMulCommClass H G α
g : H
⊢ g • s \ ⋃ g_1, ⋃ (_ : g_1 ≠ 1), g_1 • g • s = g • s \ ⋃ i, ⋃ (_ : i ≠ 1), g • i • s
Module: Mathlib.MeasureTheory.Group.FundamentalDomain

Goal state before:
pp: G : Type u_1
α : Type u_3
inst✝⁵ : Countable G
inst✝⁴ : Group G
inst✝³ : MulAction G α
inst✝² : MeasurableSpace α
μ : Measure α
s : Set α
hs : IsFundamentalDomain G s μ
inst✝¹ : MeasurableConstSMul G α
inst✝ : SMulInvariantMeasure G α μ
⊢ ∀ᵐ (x : α) ∂μ, ∃ g, g • x ∈ fundamentalInterior G s

Tactic:
simp_rw [ae_iff, not_exists, ← mem_inv_smul_set_iff, ofPred_forall, ← compl_ofPred,
      ofPred_mem_eq, ← compl_iUnion]
    have :
      ((⋃ g : G, g⁻¹ • s) \ ⋃ g : G, g⁻¹ • fundamentalFrontier G s) ⊆
        ⋃ g : G, g⁻¹ • fundamentalInterior G s := by
      simp_rw [sdiff_subset_iff, ← iUnion_union_distrib, ← smul_set_union (α := G) (β := α),
        fundamentalFrontier_union_fundamentalInterior]; rfl
    refine eq_bot_mono (μ.mono <| compl_subset_compl.2 this) ?_
    simp only [iUnion_inv_smul, compl_sdiff, ENNReal.bot_eq_zero,
      @iUnion_smul_eq_ofPred_exists _ _ _ _ s]
    exact measure_union_null
      (measure_iUnion_null fun _ => measure_smul_null hs.measure_fundamentalFrontier _) hs.ae_covers

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

Goal state before:
pp: X : Type u_1
E : Type u_3
mX : MeasurableSpace X
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : PartialOrder E
inst✝² : IsOrderedAddMonoid E
inst✝¹ : IsOrderedModule ℝ E
μ : Measure X
f g : X → E
s : Set X
inst✝ : ClosedIciTopology E
hf : IntegrableOn f s μ
hg : IntegrableOn g s μ
hs : MeasurableSet s
h : ∀ᵐ (x : X) ∂μ, x ∈ s → f x ≤ g x
⊢ ∫ (x : X) in s, f x ∂μ ≤ ∫ (x : X) in s, g x ∂μ

Tactic:
refine setIntegral_mono_ae_restrict hf hg ?_; rwa [EventuallyLE, ae_restrict_iff' hs]

Goal state after:
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
⊢ IsFiniteMeasure (Measure.map (Quotient.mk α_mod_G) (ν.restrict 𝓕))

Tactic:
have : Fact (ν 𝓕 < ∞) := by
    apply Fact.mk
    convert! Ne.lt_top h
    exact (h𝓕.covolume_eq_volume ν).symm

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
this : Fact (ν 𝓕 < ∞)
⊢ IsFiniteMeasure (Measure.map (Quotient.mk α_mod_G) (ν.restrict 𝓕))
Module: Mathlib.Analysis.InnerProductSpace.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
⊢ ↑‖x‖ ^ 2 = 0 ↔ x = 0

Tactic:
sq_eq_zero_iff,

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x : E
⊢ ↑‖x‖ = 0 ↔ x = 0
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
⊢ re ⟪x, y⟫ = (‖x + y‖ * ‖x + y‖ - ‖x - y‖ * ‖x - y‖) / 4

Tactic:
@norm_add_mul_self 𝕜,

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x y : E
⊢ re ⟪x, y⟫ = (‖x‖ * ‖x‖ + 2 * re ⟪x, y⟫ + ‖y‖ * ‖y‖ - ‖x - y‖ * ‖x - y‖) / 4
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
h : ⟪x, y⟫ = 0
⊢ ‖x + y‖ * ‖x + y‖ = ‖x‖ * ‖x‖ + ‖y‖ * ‖y‖

Tactic:
@norm_add_mul_self 𝕜,

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x y : E
h : ⟪x, y⟫ = 0
⊢ ‖x‖ * ‖x‖ + 2 * re ⟪x, y⟫ + ‖y‖ * ‖y‖ = ‖x‖ * ‖x‖ + ‖y‖ * ‖y‖
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
h : ⟪x, y⟫ = 0
⊢ ‖x + y‖ * ‖x + y‖ = ‖x‖ * ‖x‖ + ‖y‖ * ‖y‖

Tactic:
rw [@norm_add_mul_self 𝕜, add_right_cancel_iff, add_eq_left, mul_eq_zero]

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x y : E
h : ⟪x, y⟫ = 0
⊢ 2 = 0 ∨ re ⟪x, y⟫ = 0
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 : Nonempty ↑K := Nonempty.intro ⟨v, hv⟩
eq : ‖u - v‖ = ⨅ w, ‖u - ↑w‖
w : F
hw : w ∈ K
δ : ℝ := ⨅ w, ‖u - ↑w‖
p : ℝ := ⟪u - v, w - v⟫_ℝ
q : ℝ := ‖w - v‖ ^ 2
δ_le : ∀ (w : ↑K), δ ≤ ‖u - ↑w‖
δ_le' : ∀ w ∈ K, δ ≤ ‖u - w‖
θ : ℝ
hθ₁ : 0 < θ
hθ₂ : θ ≤ 1
⊢ ‖u - v‖ ^ 2 ≤ ‖u - (θ • w + (1 - θ) • v)‖ ^ 2

Tactic:
simp only [sq]; apply mul_self_le_mul_self (norm_nonneg _)
            rw [eq]; apply δ_le'
            apply h hw hv
            exacts [le_of_lt hθ₁, sub_nonneg.2 hθ₂, add_sub_cancel _ _]

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

Goal state before:
pp: 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
⊢ ∃ y r, 0 < r ∧ r ≤ B (n + 1) ∧ closedEBall y r ⊆ closedEBall x δ ∩ f n

Tactic:
refine ⟨y, min (min (δ / 2) r) (B (n + 1)), ?_, ?_, fun z hz => ⟨?_, ?_⟩⟩

Goal state after:
case refine_1
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
⊢ 0 < min (min (δ / 2) r) (B (n + 1))

case refine_2
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
⊢ min (min (δ / 2) r) (B (n + 1)) ≤ B (n + 1)

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

case refine_4
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 ∈ f n
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
F : (i : ι) → G i := fun i ↦ if i ∈ s₁ then f i else -f i
hF₁ : ∀ i ∈ s₁ \ s₂, F i = f i
hF₂ : ∀ i ∈ s₂ \ s₁, F i = -f i
hF : ∀ (i : ι), ‖F i‖ = ‖f i‖
⊢ ‖∑ i ∈ s₁ \ s₂, (V i) (F i) + ∑ i ∈ s₂ \ s₁, (V i) (F i)‖ ^ 2 = ∑ i ∈ s₁ \ s₂, ‖F i‖ ^ 2 + ∑ i ∈ s₂ \ s₁, ‖F i‖ ^ 2

Tactic:
have hs : Disjoint (s₁ \ s₂) (s₂ \ s₁) := disjoint_sdiff_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
F : (i : ι) → G i := fun i ↦ if i ∈ s₁ then f i else -f i
hF₁ : ∀ i ∈ s₁ \ s₂, F i = f i
hF₂ : ∀ i ∈ s₂ \ s₁, F i = -f i
hF : ∀ (i : ι), ‖F i‖ = ‖f i‖
hs : Disjoint (s₁ \ s₂) (s₂ \ s₁)
⊢ ‖∑ i ∈ s₁ \ s₂, (V i) (F i) + ∑ i ∈ s₂ \ s₁, (V i) (F i)‖ ^ 2 = ∑ i ∈ s₁ \ s₂, ‖F i‖ ^ 2 + ∑ i ∈ s₂ \ s₁, ‖F i‖ ^ 2
Module: Mathlib.Analysis.InnerProductSpace.Orthonormal

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁸ : RCLike 𝕜
inst✝⁷ : SeminormedAddCommGroup E
inst✝⁶ : InnerProductSpace 𝕜 E
inst✝⁵ : SeminormedAddCommGroup F
inst✝⁴ : InnerProductSpace ℝ F
ι : Type u_4
ι' : Type u_5
ι'' : Type u_6
E' : Type u_7
inst✝³ : SeminormedAddCommGroup E'
inst✝² : InnerProductSpace 𝕜 E'
E'' : Type u_8
inst✝¹ : SeminormedAddCommGroup E''
inst✝ : InnerProductSpace 𝕜 E''
f : E ≃ₗ[𝕜] E'
v : Basis ι 𝕜 E
hv : Orthonormal 𝕜 ⇑v
hf : Orthonormal 𝕜 (⇑f ∘ ⇑v)
x y : E
⊢ failed to pretty print expression (use 'set_option pp.rawOnError true' for raw representation)

Tactic:
by
    rw [← LinearEquiv.coe_coe] at hf
    rw [← v.linearCombination_repr x, ← v.linearCombination_repr y,
      ← LinearEquiv.coe_coe f, Finsupp.apply_linearCombination,
      Finsupp.apply_linearCombination, hv.inner_finsupp_eq_sum_left, hf.inner_finsupp_eq_sum_left]

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

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
ι : Type u_4
x : E
v : ι → E
s : Finset ι
hv : Orthonormal 𝕜 v
h₂ : ∑ i ∈ s, ∑ j ∈ s, ⟪v i, x⟫ * ⟪x, v j⟫ * ⟪v j, v i⟫ = ∑ k ∈ s, ⟪v k, x⟫ * ⟪x, v k⟫
⊢ ∀ (z : 𝕜), re (z * (starRingEnd 𝕜) z) = ‖z‖ ^ 2

Tactic:
intro z

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
ι : Type u_4
x : E
v : ι → E
s : Finset ι
hv : Orthonormal 𝕜 v
h₂ : ∑ i ∈ s, ∑ j ∈ s, ⟪v i, x⟫ * ⟪x, v j⟫ * ⟪v j, v i⟫ = ∑ k ∈ s, ⟪v k, x⟫ * ⟪x, v k⟫
z : 𝕜
⊢ re (z * (starRingEnd 𝕜) z) = ‖z‖ ^ 2
Module: Mathlib.Analysis.InnerProductSpace.Symmetric

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝⁴ : RCLike 𝕜
inst✝³ : SeminormedAddCommGroup E
inst✝² : InnerProductSpace 𝕜 E
F : Type u_3
inst✝¹ : SeminormedAddCommGroup F
inst✝ : InnerProductSpace 𝕜 F
T : E →ₗ[𝕜] E
f : E ≃ₗᵢ[𝕜] F
⊢ (↑f.toLinearEquiv ∘ₗ T ∘ₗ ↑f.symm.toLinearEquiv).IsSymmetric ↔ T.IsSymmetric

Tactic:
by
  refine ⟨fun h x y => ?_, fun h x y => ?_⟩
  · simpa [LinearIsometryEquiv.inner_map_eq_flip] using h (f x) (f y)
  · simp [LinearIsometryEquiv.inner_map_eq_flip, h _ (f.symm y)]

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

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
inst✝ : CompleteSpace E
T : E →ₗ[𝕜] E
hT : T.IsSymmetric
u : ℕ → E
x y : E
hu : Filter.Tendsto u Filter.atTop (nhds x)
hTu : Filter.Tendsto (⇑T ∘ u) Filter.atTop (nhds y)
hlhs : ∀ (k : ℕ), ⟪T (u k) - T x, y - T x⟫ = ⟪u k - x, T (y - T x)⟫
⊢ Filter.Tendsto (fun t ↦ ⟪u t - x, T (y - T x)⟫) Filter.atTop (nhds ⟪0, T (y - T x)⟫)

Tactic:
refine Filter.Tendsto.inner ?_ tendsto_const_nhds

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : InnerProductSpace 𝕜 E
inst✝ : CompleteSpace E
T : E →ₗ[𝕜] E
hT : T.IsSymmetric
u : ℕ → E
x y : E
hu : Filter.Tendsto u Filter.atTop (nhds x)
hTu : Filter.Tendsto (⇑T ∘ u) Filter.atTop (nhds y)
hlhs : ∀ (k : ℕ), ⟪T (u k) - T x, y - T x⟫ = ⟪u k - x, T (y - T x)⟫
⊢ Filter.Tendsto (fun t ↦ u t - x) Filter.atTop (nhds 0)
Module: Mathlib.Analysis.InnerProductSpace.Projection.Submodule

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
ι : Type u_4
inst✝¹ : Preorder ι
U : ι → Submodule 𝕜 E
inst✝ : ∀ (t : ι), (U t).HasOrthogonalProjection
hU : Monotone U
x : E
hU' : ⊤ ≤ (⨆ t, U t).topologicalClosure
⊢ (⨆ i, U i).topologicalClosure.HasOrthogonalProjection

Tactic:
rw [top_unique hU']

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : InnerProductSpace 𝕜 E
ι : Type u_4
inst✝¹ : Preorder ι
U : ι → Submodule 𝕜 E
inst✝ : ∀ (t : ι), (U t).HasOrthogonalProjection
hU : Monotone U
x : E
hU' : ⊤ ≤ (⨆ t, U t).topologicalClosure
⊢ ⊤.HasOrthogonalProjection
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: case refine_1
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
v : E
h : K.starProjection v = v
⊢ v ∈ K

Tactic:
← h

Goal state after:
case refine_1
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
v : E
h : K.starProjection v = v
⊢ K.starProjection v ∈ K
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: case refine_1
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
v : E
h : K.orthogonalProjectionOnto v = 0
⊢ v - ↑0 ∈ Kᗮ

Tactic:
← h

Goal state after:
case refine_1
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
v : E
h : K.orthogonalProjectionOnto v = 0
⊢ v - ↑(K.orthogonalProjectionOnto v) ∈ Kᗮ
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
x✝ : E
⊢ ((U.subtypeL ∘SL U.orthogonalProjectionOnto) ∘SL V.starProjection) x✝ = U.starProjection x✝

Tactic:
simp [orthogonalProjectionOnto_starProjection_of_le h]

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
K : Submodule 𝕜 E
inst✝ : K.HasOrthogonalProjection
u : ↥K
v : E
⊢ (starRingEnd 𝕜) ⟪K.orthogonalProjectionOnto v, u⟫ = (starRingEnd 𝕜) ⟪v, ↑u⟫

Tactic:
inner_orthogonalProjectionOnto_eq_of_mem_right

Goal state after:
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
⊢ (starRingEnd 𝕜) ⟪v, ↑u⟫ = (starRingEnd 𝕜) ⟪v, ↑u⟫
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 v : E
⊢ ⟪K.orthogonalProjectionOnto u, K.orthogonalProjectionOnto v⟫ = ⟪u, ↑(K.orthogonalProjectionOnto v)⟫

Tactic:
inner_orthogonalProjectionOnto_eq_of_mem_right

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
K : Submodule 𝕜 E
inst✝ : K.HasOrthogonalProjection
v : E
⊢ 0 ≤ re ⟪K.starProjection v, v⟫

Tactic:
re_inner_starProjection_eq_normSq K v

Goal state after:
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
v : E
⊢ 0 ≤ ‖K.orthogonalProjectionOnto v‖ ^ 2
Module: Mathlib.Analysis.Normed.Lp.ProdLp

Goal state before:
pp: case inr
p : ℝ≥0∞
𝕜 : Type u_1
α : Type u_2
β : Type u_3
hp : Fact (1 ≤ p)
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
f g : WithLp p (α × β)
h : 1 ≤ p.toReal
this : 0 < p.toReal
⊢ (ENNReal.ofReal (dist f.fst g.fst) ^ p.toReal + ENNReal.ofReal (dist f.snd g.snd) ^ p.toReal) ^ p.toReal⁻¹ =
    ENNReal.ofReal ((dist f.fst g.fst ^ p.toReal + dist f.snd g.snd ^ p.toReal) ^ p.toReal⁻¹)

Tactic:
rw [← ENNReal.ofReal_rpow_of_nonneg, ENNReal.ofReal_add, ← ENNReal.ofReal_rpow_of_nonneg,
        ← ENNReal.ofReal_rpow_of_nonneg] <;> simp [Real.rpow_nonneg, add_nonneg]

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

Goal state before:
pp: case mp.refine_2
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
v : Set E
hv : Orthonormal 𝕜 Subtype.val
x : E
hx' : x ∈ (span 𝕜 v)ᗮ
hx : x ≠ 0
e : E := (↑‖x‖)⁻¹ • x
he : ‖e‖ = 1
he' : e ∈ (span 𝕜 v)ᗮ
he'' : e ∉ v
⊢ Pairwise fun i j ↦ ⟪↑i, ↑j⟫_𝕜 = 0

Tactic:
have h_end : ∀ a ∈ v, ⟪a, e⟫ = 0 := by
        intro a ha
        exact he' a (Submodule.subset_span ha)
      rintro ⟨a, ha'⟩
      rcases eq_or_mem_of_mem_insert ha' with ha | ha
      · rintro ⟨b, hb'⟩ hab'
        have hb : b ∈ v := by grind
        rw [inner_eq_zero_symm]
        simpa [ha] using h_end b hb
      rintro ⟨b, hb'⟩ hab'
      rcases eq_or_mem_of_mem_insert hb' with hb | hb
      · simpa [hb] using h_end a ha
      have : (⟨a, ha⟩ : v) ≠ ⟨b, hb⟩ := by
        intro hab''
        apply hab'
        simpa using hab''
      exact hv.2 this

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

Goal state before:
pp: α : Type u_2
β : Type u_3
inst✝¹ : SeminormedAddCommGroup α
inst✝ : SeminormedAddCommGroup β
x : WithLp 2 (α × β)
⊢ ‖x‖ = √(‖x.fst‖ ^ 2 + ‖x.snd‖ ^ 2)

Tactic:
rw [prod_norm_eq_of_nat 2 (by norm_cast) _, Real.sqrt_eq_rpow]

Goal state after:
α : Type u_2
β : Type u_3
inst✝¹ : SeminormedAddCommGroup α
inst✝ : SeminormedAddCommGroup β
x : WithLp 2 (α × β)
⊢ (‖x.fst‖ ^ 2 + ‖x.snd‖ ^ 2) ^ (1 / ↑2) = (‖x.fst‖ ^ 2 + ‖x.snd‖ ^ 2) ^ (1 / 2)
Module: Mathlib.Analysis.Normed.Lp.ProdLp

Goal state before:
pp: α : Type u_2
β : Type u_3
inst✝¹ : SeminormedAddCommGroup α
inst✝ : SeminormedAddCommGroup β
x y : WithLp 2 (α × β)
⊢ dist x y = √(dist x.fst y.fst ^ 2 + dist x.snd y.snd ^ 2)

Tactic:
exact prod_dist_eq_of_L2 _ _

Goal state after:
Module: Mathlib.Data.Matrix.Reflection

Goal state before:
pp: α : Type u_1
m n : ℕ
P : Matrix (Fin (m + 1)) (Fin n) α → Prop
⊢ (∃ r A, P (of (vecCons r A))) ↔ ∃ x, P x

Tactic:
exact Iff.symm Fin.exists_fin_succ_pi

Goal state after:
Module: Mathlib.Data.Matrix.Reflection

Goal state before:
pp: l m n : ℕ
α : Type u_1
inst✝¹ : Mul α
inst✝ : AddCommMonoid α
A : Matrix (Fin l) (Fin m) α
B : Matrix (Fin m) (Fin n) α
⊢ A.mulᵣ B = A * B

Tactic:
simp [mulᵣ, Matrix.transpose]
  rfl

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

Goal state before:
pp: case inl
𝕜 : Type u_1
α : Type u_2
β : Type u_3
inst✝⁶ : SeminormedAddCommGroup α
inst✝⁵ : SeminormedAddCommGroup β
inst✝⁴ : SeminormedRing 𝕜
inst✝³ : Module 𝕜 α
inst✝² : Module 𝕜 β
inst✝¹ : IsBoundedSMul 𝕜 α
inst✝ : IsBoundedSMul 𝕜 β
c : 𝕜
hp : Fact (1 ≤ ∞)
f : WithLp ∞ (α × β)
⊢ ‖c • f.ofLp‖₊ ≤ ‖c‖₊ * ‖f.ofLp‖₊

Tactic:
exact norm_smul_le _ _

Goal state after:
Module: Mathlib.LinearAlgebra.UnitaryGroup

Goal state before:
pp: case left
n : Type u
inst✝⁵ : DecidableEq n
inst✝⁴ : Fintype n
R : Type u_1
m : Type u_2
inst✝³ : Semiring R
inst✝² : StarRing R
inst✝¹ : Fintype m
inst✝ : DecidableEq m
U₁ : Matrix n n R
U₂ : Matrix m m R
hU₁ : U₁ ∈ unitary (Matrix n n R)
hU₂ : U₂ ∈ unitary (Matrix m m R)
i✝ j✝ : n × m
⊢ ∑ x, star U₂ i✝.2 x * 1 i✝.1 j✝.1 * U₂ x j✝.2 = 1 i✝ j✝

Tactic:
Matrix.one_apply,

Goal state after:
case left
n : Type u
inst✝⁵ : DecidableEq n
inst✝⁴ : Fintype n
R : Type u_1
m : Type u_2
inst✝³ : Semiring R
inst✝² : StarRing R
inst✝¹ : Fintype m
inst✝ : DecidableEq m
U₁ : Matrix n n R
U₂ : Matrix m m R
hU₁ : U₁ ∈ unitary (Matrix n n R)
hU₂ : U₂ ∈ unitary (Matrix m m R)
i✝ j✝ : n × m
⊢ ∑ x, (star U₂ i✝.2 x * if i✝.1 = j✝.1 then 1 else 0) * U₂ x j✝.2 = if i✝ = j✝ then 1 else 0
Module: Mathlib.LinearAlgebra.UnitaryGroup

Goal state before:
pp: case left
n : Type u
inst✝⁵ : DecidableEq n
inst✝⁴ : Fintype n
R : Type u_1
m : Type u_2
inst✝³ : Semiring R
inst✝² : StarRing R
inst✝¹ : Fintype m
inst✝ : DecidableEq m
U₁ : Matrix n n R
U₂ : Matrix m m R
hU₁ : U₁ ∈ unitary (Matrix n n R)
hU₂ : U₂ ∈ unitary (Matrix m m R)
i✝ j✝ : n × m
⊢ (if i✝.1 = j✝.1 then 1 i✝.2 j✝.2 else ∑ x, 0) = if i✝ = j✝ then 1 else 0

Tactic:
Matrix.one_apply,

Goal state after:
case left
n : Type u
inst✝⁵ : DecidableEq n
inst✝⁴ : Fintype n
R : Type u_1
m : Type u_2
inst✝³ : Semiring R
inst✝² : StarRing R
inst✝¹ : Fintype m
inst✝ : DecidableEq m
U₁ : Matrix n n R
U₂ : Matrix m m R
hU₁ : U₁ ∈ unitary (Matrix n n R)
hU₂ : U₂ ∈ unitary (Matrix m m R)
i✝ j✝ : n × m
⊢ (if i✝.1 = j✝.1 then if i✝.2 = j✝.2 then 1 else 0 else ∑ x, 0) = if i✝ = j✝ then 1 else 0
Module: Mathlib.LinearAlgebra.UnitaryGroup

Goal state before:
pp: case right
n : Type u
inst✝⁵ : DecidableEq n
inst✝⁴ : Fintype n
R : Type u_1
m : Type u_2
inst✝³ : Semiring R
inst✝² : StarRing R
inst✝¹ : Fintype m
inst✝ : DecidableEq m
U₁ : Matrix n n R
U₂ : Matrix m m R
hU₁ : U₁ ∈ unitary (Matrix n n R)
hU₂ : U₂ ∈ unitary (Matrix m m R)
i✝ j✝ : n × m
⊢ ∑ x, U₁ i✝.1 x * 1 i✝.2 j✝.2 * star U₁ x j✝.1 = 1 i✝ j✝

Tactic:
Matrix.one_apply,

Goal state after:
case right
n : Type u
inst✝⁵ : DecidableEq n
inst✝⁴ : Fintype n
R : Type u_1
m : Type u_2
inst✝³ : Semiring R
inst✝² : StarRing R
inst✝¹ : Fintype m
inst✝ : DecidableEq m
U₁ : Matrix n n R
U₂ : Matrix m m R
hU₁ : U₁ ∈ unitary (Matrix n n R)
hU₂ : U₂ ∈ unitary (Matrix m m R)
i✝ j✝ : n × m
⊢ ∑ x, (U₁ i✝.1 x * if i✝.2 = j✝.2 then 1 else 0) * star U₁ x j✝.1 = if i✝ = j✝ then 1 else 0