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

Goal state before:
pp: G : Type u_1
α : Type u_3
inst✝³ : Countable G
inst✝² : Group G
inst✝¹ : MulAction G α
inst✝ : MeasurableSpace α
μ : Measure α
s : Set α
hs : IsFundamentalDomain G s μ
⊢ μ (fundamentalFrontier G s) = 0

Tactic:
simpa only [fundamentalFrontier, iUnion₂_inter, one_smul, measure_iUnion_null_iff, inter_comm s,
    Function.onFun] using! fun g (hg : g ≠ 1) => hs.aedisjoint hg

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

Goal state before:
pp: case h.h
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₁ K₂ : Compacts G
V : Set G
hV : (interior V).Nonempty
h : Disjoint (K₁.carrier * V⁻¹) (K₂.carrier * V⁻¹)
s : Finset G
h1s : K₁.carrier ∪ K₂.carrier ⊆ ⋃ g ∈ s, (fun h ↦ g * h) ⁻¹' V
h2s : s.card = index (K₁.carrier ∪ K₂.carrier) V
K : Set G
hK : K ⊆ ⋃ g ∈ s, (fun x ↦ g * x) ⁻¹' V
g : G
hg : g ∈ K
g₀ : G
h1g₀ : g₀ ∈ s
h2g₀ : g₀ * g ∈ V
⊢ g ∈ (fun h ↦ g₀ * h) ⁻¹' V

pp: case h.w
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₁ K₂ : Compacts G
V : Set G
hV : (interior V).Nonempty
h : Disjoint (K₁.carrier * V⁻¹) (K₂.carrier * V⁻¹)
s : Finset G
h1s : K₁.carrier ∪ K₂.carrier ⊆ ⋃ g ∈ s, (fun h ↦ g * h) ⁻¹' V
h2s : s.card = index (K₁.carrier ∪ K₂.carrier) V
K : Set G
hK : K ⊆ ⋃ g ∈ s, (fun x ↦ g * x) ⁻¹' V
g : G
hg : g ∈ K
g₀ : G
h1g₀ : g₀ ∈ s
h2g₀ : g₀ * g ∈ V
⊢ g₀ ∈ {g ∈ s | ((fun x ↦ g * x) ⁻¹' V ∩ K).Nonempty}

Tactic:
swap

Goal state after:
case h.w
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₁ K₂ : Compacts G
V : Set G
hV : (interior V).Nonempty
h : Disjoint (K₁.carrier * V⁻¹) (K₂.carrier * V⁻¹)
s : Finset G
h1s : K₁.carrier ∪ K₂.carrier ⊆ ⋃ g ∈ s, (fun h ↦ g * h) ⁻¹' V
h2s : s.card = index (K₁.carrier ∪ K₂.carrier) V
K : Set G
hK : K ⊆ ⋃ g ∈ s, (fun x ↦ g * x) ⁻¹' V
g : G
hg : g ∈ K
g₀ : G
h1g₀ : g₀ ∈ s
h2g₀ : g₀ * g ∈ V
⊢ g₀ ∈ {g ∈ s | ((fun x ↦ g * x) ⁻¹' V ∩ K).Nonempty}

case h.h
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₁ K₂ : Compacts G
V : Set G
hV : (interior V).Nonempty
h : Disjoint (K₁.carrier * V⁻¹) (K₂.carrier * V⁻¹)
s : Finset G
h1s : K₁.carrier ∪ K₂.carrier ⊆ ⋃ g ∈ s, (fun h ↦ g * h) ⁻¹' V
h2s : s.card = index (K₁.carrier ∪ K₂.carrier) V
K : Set G
hK : K ⊆ ⋃ g ∈ s, (fun x ↦ g * x) ⁻¹' V
g : G
hg : g ∈ K
g₀ : G
h1g₀ : g₀ ∈ s
h2g₀ : g₀ * g ∈ V
⊢ g ∈ (fun h ↦ g₀ * h) ⁻¹' V
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: case pos
X : Type u_1
mX : MeasurableSpace X
μ : Measure X
f : X → ℝ
s : Set X
hs : ∀ x ∈ s, f x ≤ 1
h's : ∀ x ∈ sᶜ, f x ≤ 0
H : Integrable f μ
⊢ ENNReal.ofReal (∫ (x : X), f x ∂μ) ≤ μ s

pp: case neg
X : Type u_1
mX : MeasurableSpace X
μ : Measure X
f : X → ℝ
s : Set X
hs : ∀ x ∈ s, f x ≤ 1
h's : ∀ x ∈ sᶜ, f x ≤ 0
H : ¬Integrable f μ
⊢ ENNReal.ofReal (∫ (x : X), f x ∂μ) ≤ μ s

Tactic:
swap

Goal state after:
case neg
X : Type u_1
mX : MeasurableSpace X
μ : Measure X
f : X → ℝ
s : Set X
hs : ∀ x ∈ s, f x ≤ 1
h's : ∀ x ∈ sᶜ, f x ≤ 0
H : ¬Integrable f μ
⊢ ENNReal.ofReal (∫ (x : X), f x ∂μ) ≤ μ s

case pos
X : Type u_1
mX : MeasurableSpace X
μ : Measure X
f : X → ℝ
s : Set X
hs : ∀ x ∈ s, f x ≤ 1
h's : ∀ x ∈ sᶜ, f x ≤ 0
H : Integrable f μ
⊢ ENNReal.ofReal (∫ (x : X), f x ∂μ) ≤ μ s
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: case pos
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)
⊢ ∫ (x : X) in s, f x ∂μ ≤ ∫ (x : X) in s, g x ∂μ

pp: case neg
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)
⊢ ∫ (x : X) in s, f x ∂μ ≤ ∫ (x : X) in s, g x ∂μ

Tactic:
swap

Goal state after:
case neg
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)
⊢ ∫ (x : X) in s, f x ∂μ ≤ ∫ (x : X) in s, g x ∂μ

case pos
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)
⊢ ∫ (x : X) in s, f x ∂μ ≤ ∫ (x : X) in s, g x ∂μ
Module: Mathlib.MeasureTheory.Integral.Bochner.Set

Goal state before:
pp: X : Type u_1
F : Type u_4
mX : MeasurableSpace X
𝕜 : Type u_5
inst✝³ : NormedRing 𝕜
inst✝² : NormedAddCommGroup F
inst✝¹ : Module 𝕜 F
inst✝ : IsBoundedSMul 𝕜 F
p : ℝ≥0∞
μ : Measure X
c : 𝕜
f : ↥(Lp F p μ)
s : Set X
⊢ MemLp.toLp ↑↑(c • f) ⋯ = c • MemLp.toLp ↑↑f ⋯

Tactic:
ext1
  refine (ae_restrict_of_ae (Lp.coeFn_smul c f)).mp ?_
  refine (MemLp.coeFn_toLp ((Lp.memLp f).restrict s)).mp ?_
  refine (MemLp.coeFn_toLp ((Lp.memLp (c • f)).restrict s)).mp ?_
  refine
    (Lp.coeFn_smul c (MemLp.toLp f ((Lp.memLp f).restrict s))).mono fun x hx1 hx2 hx3 hx4 => ?_
  simp only [hx2, hx1, hx3, hx4, Pi.smul_apply]

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

Goal state before:
pp: case inr
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
ha : (𝓝[<] a).NeBot
⊢ leftLim (↑(c • f)) a = ↑c * leftLim (↑f) a

Tactic:
exact tendsto_nhds_unique ((c • f).mono.tendsto_leftLim a)
        ((f.mono.tendsto_leftLim a).const_smul c)

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
⊢ (c • f).measure = c • f.measure

Tactic:
refine Measure.ext_of_Icc _ _ (fun a b h ↦ ?_)
  simp only [measure_Icc, Measure.smul_apply]
  change ofReal (c * f b - leftLim (c • f) a) = c • ofReal (f b - leftLim f a)
  have : leftLim (c • f) a = c * leftLim f a := by
    rcases Filter.eq_or_neBot (𝓝[<] a) with ha | ha
    · simp [leftLim_eq_of_eq_bot _ ha]
      rfl
    · exact tendsto_nhds_unique ((c • f).mono.tendsto_leftLim a)
        ((f.mono.tendsto_leftLim a).const_smul c)
  rw [this, ← _root_.mul_sub, ENNReal.ofReal_mul zero_le_coe, ofReal_coe_nnreal, ← smul_eq_mul]
  rfl

Goal state after:
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‖ = 0
⊢ ‖x‖ * ‖y‖ ≤ 0

Tactic:
simp [h]

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

Goal state before:
pp: G : Type u_1
inst✝⁴ : Group G
inst✝³ : TopologicalSpace G
inst✝² : IsTopologicalGroup G
inst✝¹ : MeasurableSpace G
inst✝ : BorelSpace G
K₀ : PositiveCompacts G
⊢ (haarMeasure K₀).IsMulLeftInvariant

Tactic:
← forall_measure_preimage_mul_iff

Goal state after:
G : Type u_1
inst✝⁴ : Group G
inst✝³ : TopologicalSpace G
inst✝² : IsTopologicalGroup G
inst✝¹ : MeasurableSpace G
inst✝ : BorelSpace G
K₀ : PositiveCompacts G
⊢ ∀ (g : G) (A : Set G), MeasurableSet A → (haarMeasure K₀) ((fun h ↦ g * h) ⁻¹' A) = (haarMeasure K₀) A
Module: Mathlib.Analysis.InnerProductSpace.Basic

Goal state before:
pp: F : Type u_3
inst✝¹ : SeminormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
ι₁ : Type u_4
s₁ : Finset ι₁
w₁ : ι₁ → ℝ
v₁ : ι₁ → F
h₁ : ∑ i ∈ s₁, w₁ i = 0
ι₂ : Type u_5
s₂ : Finset ι₂
w₂ : ι₂ → ℝ
v₂ : ι₂ → F
h₂ : ∑ i ∈ s₂, w₂ i = 0
⊢ ∑ x ∈ s₁,
      ∑ x_1 ∈ s₂,
        w₁ x * (w₂ x_1 * (‖v₁ x‖ * ‖v₁ x‖ / 2 + ‖v₂ x_1‖ * ‖v₂ x_1‖ / 2 - ‖v₁ x - v₂ x_1‖ * ‖v₁ x - v₂ x_1‖ / 2)) =
    (-∑ i₁ ∈ s₁, ∑ i₂ ∈ s₂, w₁ i₁ * w₂ i₂ * (‖v₁ i₁ - v₂ i₂‖ * ‖v₁ i₁ - v₂ i₂‖)) / 2

Tactic:
mul_sub_left_distrib,

Goal state after:
F : Type u_3
inst✝¹ : SeminormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
ι₁ : Type u_4
s₁ : Finset ι₁
w₁ : ι₁ → ℝ
v₁ : ι₁ → F
h₁ : ∑ i ∈ s₁, w₁ i = 0
ι₂ : Type u_5
s₂ : Finset ι₂
w₂ : ι₂ → ℝ
v₂ : ι₂ → F
h₂ : ∑ i ∈ s₂, w₂ i = 0
⊢ ∑ x ∈ s₁,
      ∑ x_1 ∈ s₂,
        (w₁ x * (w₂ x_1 * (‖v₁ x‖ * ‖v₁ x‖ / 2 + ‖v₂ x_1‖ * ‖v₂ x_1‖ / 2)) -
          w₁ x * (w₂ x_1 * (‖v₁ x - v₂ x_1‖ * ‖v₁ x - v₂ x_1‖ / 2))) =
    (-∑ i₁ ∈ s₁, ∑ i₂ ∈ s₂, w₁ i₁ * w₂ i₂ * (‖v₁ i₁ - v₂ i₂‖ * ‖v₁ i₁ - v₂ i₂‖)) / 2
Module: Mathlib.Analysis.InnerProductSpace.Basic

Goal state before:
pp: case ha
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x y : E
hx₀ : ¬x = 0
this✝ : ‖x‖ ^ 2 ≠ 0
this : InnerProductSpace.Core 𝕜 E := InnerProductSpace.toCore
h : ⟪x, y⟫ • x = ⟪x, x⟫ • y
⊢ ⟪x, x⟫ ≠ 0

Tactic:
rwa [inner_self_ne_zero]

Goal state after:
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 y : E
h₀ : x ≠ 0
h₀' : ¬↑‖x‖ = 0
h : ⟪x, y⟫ = ↑‖x‖ * ↑‖y‖
⊢ ‖⟪x, y⟫‖ = ‖x‖ * ‖y‖

Tactic:
simp [h]

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

Goal state before:
pp: F : Type u_3
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
x y : F
⊢ ⟪x, y⟫_ℝ / (‖x‖ * ‖y‖) = -1 ↔ x ≠ 0 ∧ ∃ r < 0, y = r • x

Tactic:
rw [← neg_eq_iff_eq_neg, ← neg_div, ← inner_neg_right, ← norm_neg y,
    real_inner_div_norm_mul_norm_eq_one_iff, (@neg_surjective ℝ _).exists]

Goal state after:
F : Type u_3
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
x y : F
⊢ (x ≠ 0 ∧ ∃ x_1, 0 < -x_1 ∧ -y = -x_1 • x) ↔ x ≠ 0 ∧ ∃ r < 0, y = r • x
Module: Mathlib.Analysis.InnerProductSpace.LinearMap

Goal state before:
pp: V : Type u_4
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℂ V
S T : V →ₗ[ℂ] V
⊢ (∀ (x : V), ⟪S x, x⟫_ℂ = ⟪T x, x⟫_ℂ) ↔ S = T

Tactic:
by
  rw [← sub_eq_zero, ← inner_map_self_eq_zero]
  refine forall_congr' fun x => ?_
  rw [LinearMap.sub_apply, inner_sub_left, sub_eq_zero]

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

Goal state before:
pp: case inl
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
x : E
h : ‖x‖ = 0
⊢ ‖x‖ ≤ ‖(innerSL 𝕜) x‖

Tactic:
simp [h]

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
s : Set E
hs : Orthonormal 𝕜 Subtype.val
⊢ ∃ w ⊇ s, Orthonormal 𝕜 Subtype.val ∧ ∀ u ⊇ w, Orthonormal 𝕜 Subtype.val → u = w

Tactic:
have := zorn_subset_nonempty { b | Orthonormal 𝕜 (Subtype.val : b → E) } ?_ _ hs

Goal state after:
case refine_2
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
this : ∃ m, s ⊆ m ∧ Maximal (fun x ↦ x ∈ {b | Orthonormal 𝕜 Subtype.val}) m
⊢ ∃ w ⊇ s, Orthonormal 𝕜 Subtype.val ∧ ∀ u ⊇ w, Orthonormal 𝕜 Subtype.val → u = w

case 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 ⊆ {b | Orthonormal 𝕜 Subtype.val},
    IsChain (fun x1 x2 ↦ x1 ⊆ x2) c → c.Nonempty → ∃ ub ∈ {b | Orthonormal 𝕜 Subtype.val}, ∀ s ∈ c, s ⊆ ub
Module: Mathlib.Analysis.InnerProductSpace.LinearMap

Goal state before:
pp: 𝕜 : Type u_4
inst✝² : RCLike 𝕜
F : Type u_8
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace 𝕜 F
x : F
hx : x ≠ 0
⊢ IsIdempotentElem (((rankOne 𝕜) x) x) ↔ ‖x‖ = 1

Tactic:
refine ⟨?_, isIdempotentElem_rankOne_self⟩

Goal state after:
𝕜 : Type u_4
inst✝² : RCLike 𝕜
F : Type u_8
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace 𝕜 F
x : F
hx : x ≠ 0
⊢ IsIdempotentElem (((rankOne 𝕜) x) x) → ‖x‖ = 1
Module: Mathlib.Analysis.InnerProductSpace.LinearMap

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
T : E →L[𝕜] F
C : ℝ
hC : 0 ≤ C
h : ∀ (x : E) (y : F), ‖x‖ = 1 → ‖y‖ = 1 → re ⟪T x, y⟫_𝕜 ≤ C
⊢ ‖T‖ ≤ C

Tactic:
by
  refine opNorm_le_of_unit_norm hC fun x hx ↦ ?_
  by_cases hTx : ‖T x‖ = 0
  · rwa [hTx]
  · specialize h x (((‖T x‖⁻¹ : ℝ) : 𝕜) • T x) hx (by simp [norm_smul, hTx])
    rwa [inner_smul_right, re_ofReal_mul, ← norm_sq_eq_re_inner,
      inv_mul_eq_div, sq, mul_self_div_self] at h

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
center : ℕ → X → ℝ≥0∞ → X
radius : ℕ → X → ℝ≥0∞ → ℝ≥0∞
Hpos : ∀ (n : ℕ) (x : X) (δ : ℝ≥0∞), δ ≠ 0 → 0 < radius n x δ
HB : ∀ (n : ℕ) (x : X) (δ : ℝ≥0∞), δ ≠ 0 → radius n x δ ≤ B (n + 1)
Hball : ∀ (n : ℕ) (x : X) (δ : ℝ≥0∞), δ ≠ 0 → closedEBall (center n x δ) (radius n x δ) ⊆ closedEBall x δ ∩ f n
x : X
ε : ℝ≥0∞
εpos : 0 < ε
F : ℕ → X × ℝ≥0∞ := fun n ↦ Nat.recOn n (x, min ε (B 0)) fun n p ↦ (center n p.1 p.2, radius n p.1 p.2)
c : ℕ → X := fun n ↦ (F n).1
r : ℕ → ℝ≥0∞ := fun n ↦ (F n).2
rpos : ∀ (n : ℕ), 0 < r n
r0 : ∀ (n : ℕ), r n ≠ 0
rB : ∀ (n : ℕ), r n ≤ B n
incl : ∀ (n : ℕ), closedEBall (c (n + 1)) (r (n + 1)) ⊆ closedEBall (c n) (r n) ∩ f n
cdist : ∀ (n : ℕ), edist (c n) (c (n + 1)) ≤ B n
this : CauchySeq c
y : X
ylim : Tendsto c atTop (nhds y)
⊢ ∃ y ∈ ⋂ n, f n, y ∈ closedEBall x ε

Tactic:
use y

Goal state after:
case h
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : IsCompletelyPseudoMetrizableSpace X
x✝ : UpgradedIsCompletelyPseudoMetrizableSpace X := ⋯
f : ℕ → Set X
ho : ∀ (n : ℕ), IsOpen (f n)
hd : ∀ (n : ℕ), Dense (f n)
B : ℕ → ℝ≥0∞ := ⋯
Bpos : ∀ (n : ℕ), 0 < B n
center : ℕ → X → ℝ≥0∞ → X
radius : ℕ → X → ℝ≥0∞ → ℝ≥0∞
Hpos : ∀ (n : ℕ) (x : X) (δ : ℝ≥0∞), δ ≠ 0 → 0 < radius n x δ
HB : ∀ (n : ℕ) (x : X) (δ : ℝ≥0∞), δ ≠ 0 → radius n x δ ≤ B (n + 1)
Hball : ∀ (n : ℕ) (x : X) (δ : ℝ≥0∞), δ ≠ 0 → closedEBall (center n x δ) (radius n x δ) ⊆ closedEBall x δ ∩ f n
x : X
ε : ℝ≥0∞
εpos : 0 < ε
F : ℕ → X × ℝ≥0∞ := ⋯
c : ℕ → X := ⋯
r : ℕ → ℝ≥0∞ := ⋯
rpos : ∀ (n : ℕ), 0 < r n
r0 : ∀ (n : ℕ), r n ≠ 0
rB : ∀ (n : ℕ), r n ≤ B n
incl : ∀ (n : ℕ), closedEBall (c (n + 1)) (r (n + 1)) ⊆ closedEBall (c n) (r n) ∩ f n
cdist : ∀ (n : ℕ), edist (c n) (c (n + 1)) ≤ B n
this : CauchySeq c
y : X
ylim : Tendsto c atTop (nhds y)
⊢ y ∈ ⋂ n, f n ∧ y ∈ closedEBall x ε
Module: Mathlib.Topology.Algebra.Module.ClosedSubmodule

Goal state before:
pp: ι : Sort u_1
R : Type u_2
M : Type u_3
N : Type u_4
O : Type u_5
inst✝⁹ : Semiring R
inst✝⁸ : AddCommMonoid M
inst✝⁷ : TopologicalSpace M
inst✝⁶ : Module R M
inst✝⁵ : AddCommMonoid N
inst✝⁴ : TopologicalSpace N
inst✝³ : Module R N
inst✝² : AddCommMonoid O
inst✝¹ : TopologicalSpace O
inst✝ : Module R O
s t : ClosedSubmodule R M
x : M
S : Set (ClosedSubmodule R M)
⊢ IsClosed (⨅ s ∈ S, ↑s).carrier

Tactic:
simpa using isClosed_biInter fun x hx ↦ x.isClosed

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

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
ι : Type u_4
V : ι → Submodule 𝕜 E
hV : OrthogonalFamily 𝕜 (fun i ↦ ↥(V i)) fun i ↦ (V i).subtypeₗᵢ
v : Π₀ (i : ι), ↥(V i)
hv : ((DFinsupp.lsum ℕ) fun i ↦ (V i).subtype) v = 0
i : ι
this : ⟪↑(v i), ↑(v i)⟫ = 0
⊢ ↑(v i) = ↑(0 i)

Tactic:
simpa only [inner_self_eq_zero] using! this

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

Goal state before:
pp: F : Type u_3
inst✝¹ : NormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
v w : F
h : ‖v‖ = ‖w‖
R : F ≃ₗᵢ[ℝ] F := (ℝ ∙ (v - w))ᗮ.reflection
this : R v + R v = w + w
⊢ R v = w

Tactic:
apply smul_right_injective F (by simp : (2 : ℝ) ≠ 0)
    simpa [two_smul] using this

Goal state after:
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
S T : E →ₗ[𝕜] E
hS : S.IsSymmetricProjection
hT : T.IsSymmetricProjection
h : S.range = T.range
⊢ S.range = T.range ∧ S.rangeᗮ = T.rangeᗮ

Tactic:
simp [h]

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
⊢ LinearMap.det ↑K.reflection.toLinearEquiv = (-1) ^ finrank 𝕜 ↥Kᗮ

pp: case neg
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
⊢ LinearMap.det ↑K.reflection.toLinearEquiv = (-1) ^ finrank 𝕜 ↥Kᗮ

Tactic:
swap

Goal state after:
case neg
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
⊢ LinearMap.det ↑K.reflection.toLinearEquiv = (-1) ^ finrank 𝕜 ↥Kᗮ

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
⊢ LinearMap.det ↑K.reflection.toLinearEquiv = (-1) ^ finrank 𝕜 ↥Kᗮ
Module: Mathlib.Analysis.InnerProductSpace.Projection.FiniteDimensional

Goal state before:
pp: 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
W : Submodule ℝ F := (↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).ker
hW : ∀ w ∈ W, φ w = w
hn' : ¬finrank ℝ ↥Wᗮ ≤ n
this✝¹ : 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
hn : finrank ℝ ↥Wᗮ ≤ n + 1
this✝ : finrank ℝ ↥W + 1 ≤ finrank ℝ ↥V
this : finrank ℝ ↥V + finrank ℝ ↥Vᗮ = finrank ℝ F
⊢ finrank ℝ ↥Vᗮ ≤ n

Tactic:
have : finrank ℝ W + finrank ℝ Wᗮ = finrank ℝ F := W.finrank_add_finrank_orthogonal

Goal state after:
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
W : Submodule ℝ F := (↑(ContinuousLinearMap.id ℝ F - ↑↑φ)).ker
hW : ∀ w ∈ W, φ w = w
hn' : ¬finrank ℝ ↥Wᗮ ≤ n
this✝² : 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
hn : finrank ℝ ↥Wᗮ ≤ n + 1
this✝¹ : finrank ℝ ↥W + 1 ≤ finrank ℝ ↥V
this✝ : finrank ℝ ↥V + finrank ℝ ↥Vᗮ = finrank ℝ F
this : finrank ℝ ↥W + finrank ℝ ↥Wᗮ = finrank ℝ F
⊢ finrank ℝ ↥Vᗮ ≤ n
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 : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
x y : WithLp p (α × β)
⊢ nndist x.fst y.fst ≤ nndist x y

Tactic:
by
  simpa [← coe_nnreal_ennreal_nndist] using edist_fst_le x y

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 : SeminormedAddCommGroup α
inst✝ : SeminormedAddCommGroup β
x : WithLp p (α × β)
⊢ ‖x.snd‖ ≤ ‖x‖

Tactic:
by
  simpa using dist_snd_le x 0

Goal state after:
Module: Mathlib.Analysis.Normed.Operator.Banach

Goal state before:
pp: 𝕜 : Type u_1
𝕜' : Type u_2
inst✝¹⁰ : NontriviallyNormedField 𝕜
inst✝⁹ : NontriviallyNormedField 𝕜'
σ : 𝕜 →+* 𝕜'
E : Type u_3
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
F : Type u_4
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace 𝕜' F
f : E →SL[σ] F
σ' : 𝕜' →+* 𝕜
inst✝⁴ : RingHomInvPair σ σ'
inst✝³ : RingHomIsometric σ
inst✝² : RingHomIsometric σ'
inst✝¹ : CompleteSpace F
inst✝ : CompleteSpace E
surj : Surjective ⇑f
C : ℝ
C0 : C ≥ 0
g : F → E
hg : ∀ (y : F), dist (f (g y)) y ≤ 1 / 2 * ‖y‖ ∧ ‖g y‖ ≤ C * ‖y‖
h : F → F := fun y ↦ y - f (g y)
hle : ∀ (y : F), ‖h y‖ ≤ 1 / 2 * ‖y‖
y : F
hnle : ∀ (n : ℕ), ‖h^[n] y‖ ≤ (1 / 2) ^ n * ‖y‖
u : ℕ → E := fun n ↦ g (h^[n] y)
ule : ∀ (n : ℕ), ‖u n‖ ≤ (1 / 2) ^ n * (C * ‖y‖)
sNu : Summable fun n ↦ ‖u n‖
su : Summable u
x : E := tsum u
x_ineq : ‖x‖ ≤ (2 * C + 1) * ‖y‖
fsumeq : ∀ (n : ℕ), f (∑ i ∈ Finset.range n, u i) = y - h^[n] y
this : Tendsto (fun n ↦ ∑ i ∈ Finset.range n, u i) atTop (𝓝 x)
L₁ : Tendsto (fun n ↦ y - h^[n] y) atTop (𝓝 (f x))
L₂ : Tendsto (fun n ↦ y - h^[n] y) atTop (𝓝 (y - 0))
feq : f x = y - 0
⊢ ∃ x, f x = y ∧ ‖x‖ ≤ (2 * C + 1) * ‖y‖

Tactic:
rw [sub_zero] at feq

Goal state after:
𝕜 : Type u_1
𝕜' : Type u_2
inst✝¹⁰ : NontriviallyNormedField 𝕜
inst✝⁹ : NontriviallyNormedField 𝕜'
σ : 𝕜 →+* 𝕜'
E : Type u_3
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
F : Type u_4
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace 𝕜' F
f : E →SL[σ] F
σ' : 𝕜' →+* 𝕜
inst✝⁴ : RingHomInvPair σ σ'
inst✝³ : RingHomIsometric σ
inst✝² : RingHomIsometric σ'
inst✝¹ : CompleteSpace F
inst✝ : CompleteSpace E
surj : Surjective ⇑f
C : ℝ
C0 : C ≥ 0
g : F → E
hg : ∀ (y : F), dist (f (g y)) y ≤ 1 / 2 * ‖y‖ ∧ ‖g y‖ ≤ C * ‖y‖
h : F → F := fun y ↦ y - f (g y)
hle : ∀ (y : F), ‖h y‖ ≤ 1 / 2 * ‖y‖
y : F
hnle : ∀ (n : ℕ), ‖h^[n] y‖ ≤ (1 / 2) ^ n * ‖y‖
u : ℕ → E := fun n ↦ g (h^[n] y)
ule : ∀ (n : ℕ), ‖u n‖ ≤ (1 / 2) ^ n * (C * ‖y‖)
sNu : Summable fun n ↦ ‖u n‖
su : Summable u
x : E := tsum u
x_ineq : ‖x‖ ≤ (2 * C + 1) * ‖y‖
fsumeq : ∀ (n : ℕ), f (∑ i ∈ Finset.range n, u i) = y - h^[n] y
this : Tendsto (fun n ↦ ∑ i ∈ Finset.range n, u i) atTop (𝓝 x)
L₁ : Tendsto (fun n ↦ y - h^[n] y) atTop (𝓝 (f x))
L₂ : Tendsto (fun n ↦ y - h^[n] y) atTop (𝓝 (y - 0))
feq : f x = y
⊢ ∃ x, f x = y ∧ ‖x‖ ≤ (2 * C + 1) * ‖y‖
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 1 (α × β)
⊢ ‖x.fst - y.fst‖ + ‖(x - y).snd‖ = ‖x.fst - y.fst‖ + ‖x.snd - y.snd‖

Tactic:
sub_snd

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‖ ^ 2 = ‖x.fst‖ ^ 2 + ‖x.snd‖ ^ 2

Tactic:
by
  suffices ‖x‖₊ ^ 2 = ‖x.fst‖₊ ^ 2 + ‖x.snd‖₊ ^ 2 by
    simpa only [NNReal.coe_sum] using! congr_arg ((↑) : ℝ≥0 → ℝ) this
  rw [prod_nnnorm_eq_of_L2, NNReal.sq_sqrt]

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 y : WithLp 2 (α × β)
⊢ √(‖x.fst - y.fst‖ ^ 2 + ‖(x - y).snd‖ ^ 2) = √(‖x.fst - y.fst‖ ^ 2 + ‖x.snd - y.snd‖ ^ 2)

Tactic:
sub_snd

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

Goal state before:
pp: ι : Type u_2
β : ι → Type u_4
inst✝¹ : Fintype ι
inst✝ : (i : ι) → SeminormedAddCommGroup (β i)
x : PiLp 2 β
⊢ ‖x‖ = √(∑ i, ‖x.ofLp i‖ ^ 2)

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

Goal state after: