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

Goal state before:
pp: case h.refine_2
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₀ : PositiveCompacts G
K₁ K₂ : Compacts G
h : Disjoint K₁.carrier K₂.carrier
h₂ : IsClosed[inst✝¹] K₂.carrier
U₁ U₂ : Set G
h1U₁ : IsOpen[inst✝¹] U₁
h1U₂ : IsOpen[inst✝¹] U₂
h2U₁ : K₁.carrier ⊆ U₁
h2U₂ : K₂.carrier ⊆ U₂
hU : Disjoint U₁ U₂
L₁ : Set G
h1L₁ : L₁ ∈ 𝓝 1
V₁ : Set G
h1V₁ : V₁ ⊆ L₁
h2V₁ : IsOpen[inst✝¹] V₁
h3V₁ : 1 ∈ V₁
h2L₁ : K₁.carrier * V₁ ⊆ U₁
L₂ : Set G
h1L₂ : L₂ ∈ 𝓝 1
V₂ : Set G
h1V₂ : V₂ ⊆ L₂
h2V₂ : IsOpen[inst✝¹] V₂
h3V₂ : 1 ∈ V₂
h2L₂ : K₂.carrier * V₂ ⊆ U₂
eval : (Compacts G → ℝ) → ℝ := fun f ↦ f K₁ + f K₂ - f (K₁ ⊔ K₂)
this : Continuous eval
V : Set G := V₁ ∩ V₂
U : Set G
h1U : U ⊆ ↑{ carrier := V⁻¹, is_open' := ⋯, mem' := ⋯ }.toOpens
h2U : IsOpen[inst✝¹] U
h3U : 1 ∈ U
⊢ K₂.carrier * U⁻¹ ⊆ U₂

Tactic:
refine Subset.trans (mul_subset_mul Subset.rfl ?_) h2L₂

Goal state after:
case h.refine_2
G : Type u_1
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : IsTopologicalGroup G
K₀ : PositiveCompacts G
K₁ K₂ : Compacts G
h : Disjoint K₁.carrier K₂.carrier
h₂ : IsClosed[inst✝¹] K₂.carrier
U₁ U₂ : Set G
h1U₁ : IsOpen[inst✝¹] U₁
h1U₂ : IsOpen[inst✝¹] U₂
h2U₁ : K₁.carrier ⊆ U₁
h2U₂ : K₂.carrier ⊆ U₂
hU : Disjoint U₁ U₂
L₁ : Set G
h1L₁ : L₁ ∈ 𝓝 1
V₁ : Set G
h1V₁ : V₁ ⊆ L₁
h2V₁ : IsOpen[inst✝¹] V₁
h3V₁ : 1 ∈ V₁
h2L₁ : K₁.carrier * V₁ ⊆ U₁
L₂ : Set G
h1L₂ : L₂ ∈ 𝓝 1
V₂ : Set G
h1V₂ : V₂ ⊆ L₂
h2V₂ : IsOpen[inst✝¹] V₂
h3V₂ : 1 ∈ V₂
h2L₂ : K₂.carrier * V₂ ⊆ U₂
eval : (Compacts G → ℝ) → ℝ := fun f ↦ f K₁ + f K₂ - f (K₁ ⊔ K₂)
this : Continuous eval
V : Set G := V₁ ∩ V₂
U : Set G
h1U : U ⊆ ↑{ carrier := V⁻¹, is_open' := ⋯, mem' := ⋯ }.toOpens
h2U : IsOpen[inst✝¹] U
h3U : 1 ∈ U
⊢ U⁻¹ ⊆ V₂
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‖ ^ 2 + 2 * re ⟪x, -y⟫ + ‖y‖ ^ 2 = ‖x‖ ^ 2 - 2 * re ⟪x, y⟫ + ‖y‖ ^ 2

Tactic:
inner_neg_right,

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
⊢ ‖x‖ ^ 2 + 2 * re (-⟪x, y⟫) + ‖y‖ ^ 2 = ‖x‖ ^ 2 - 2 * re ⟪x, y⟫ + ‖y‖ ^ 2
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‖ ^ 2 + 2 * -re ⟪x, y⟫ + ‖y‖ ^ 2 = ‖x‖ ^ 2 - 2 * re ⟪x, y⟫ + ‖y‖ ^ 2

Tactic:
mul_neg,

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
⊢ ‖x‖ ^ 2 + -(2 * re ⟪x, y⟫) + ‖y‖ ^ 2 = ‖x‖ ^ 2 - 2 * re ⟪x, y⟫ + ‖y‖ ^ 2
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)
norm_tendsto : Tendsto (fun n ↦ ‖u - ↑(w n)‖) atTop (𝓝 δ)
b✝ : ℕ → ℝ := fun n ↦ 8 * δ * (1 / (↑n + 1)) + 4 * (1 / (↑n + 1)) * (1 / (↑n + 1))
p q N : ℕ
hp : N ≤ p
hq : N ≤ q
wp : F := ↑(w p)
wq : F := ↑(w q)
a : F := u - wq
b : F := u - wp
half : ℝ := 1 / 2
div : ℝ := 1 / (↑N + 1)
this : 4 * ‖u - half • (wq + wp)‖ * ‖u - half • (wq + wp)‖ + ‖wp - wq‖ * ‖wp - wq‖ = 2 * (‖a‖ * ‖a‖ + ‖b‖ * ‖b‖)
⊢ δ ≤ ‖u - half • (wq + wp)‖

Tactic:
smul_add

Goal state after:
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)
norm_tendsto : Tendsto (fun n ↦ ‖u - ↑(w n)‖) atTop (𝓝 δ)
b✝ : ℕ → ℝ := fun n ↦ 8 * δ * (1 / (↑n + 1)) + 4 * (1 / (↑n + 1)) * (1 / (↑n + 1))
p q N : ℕ
hp : N ≤ p
hq : N ≤ q
wp : F := ↑(w p)
wq : F := ↑(w q)
a : F := u - wq
b : F := u - wp
half : ℝ := 1 / 2
div : ℝ := 1 / (↑N + 1)
this : 4 * ‖u - half • (wq + wp)‖ * ‖u - half • (wq + wp)‖ + ‖wp - wq‖ * ‖wp - wq‖ = 2 * (‖a‖ * ‖a‖ + ‖b‖ * ‖b‖)
⊢ δ ≤ ‖u - (half • wq + half • wp)‖
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
⊢ ⟪x, y⟫ = ↑‖x‖ * ↑‖y‖ ↔ (↑‖y‖ / ↑‖x‖) • x = y

Tactic:
by
  have h₀' := h₀
  rw [← norm_ne_zero_iff, Ne, ← @ofReal_eq_zero 𝕜] at h₀'
  constructor <;> intro h
  · have : x = 0 ∨ y = (⟪x, y⟫ / ⟪x, x⟫ : 𝕜) • x :=
      ((norm_inner_eq_norm_tfae 𝕜 x y).out 0 1).1 (by simp [h])
    rw [this.resolve_left h₀, h]
    simp [norm_smul, mul_div_cancel_right₀ _ h₀']
  · conv_lhs => rw [← h, inner_smul_right, inner_self_eq_norm_sq_to_K]
    field

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
v : ι → E
hv : Orthonormal 𝕜 v
l : ι →₀ 𝕜
⊢ (linearCombination 𝕜 v) l = 0 → l = 0

Tactic:
hl

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
v : ι → E
hv : Orthonormal 𝕜 v
l : ι →₀ 𝕜
hl : (linearCombination 𝕜 v) l = 0
⊢ l = 0
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
v : ι → E
hv : Orthonormal 𝕜 v
l : ι →₀ 𝕜
hl : (linearCombination 𝕜 v) l = 0
i : ι
⊢ ⟪v i, (linearCombination 𝕜 v) l⟫ = ⟪v i, 0⟫

Tactic:
hl

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
v : ι → E
hv : Orthonormal 𝕜 v
l : ι →₀ 𝕜
hl : (linearCombination 𝕜 v) l = 0
i : ι
⊢ ⟪v i, 0⟫ = ⟪v i, 0⟫
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) ↔ ∀ (x : V), ⟪(S - T) x, x⟫_ℂ = 0

Tactic:
refine forall_congr' fun x => ?_

Goal state after:
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) x, x⟫_ℂ = 0
Module: Mathlib.Topology.Baire.CompleteMetrizable

Goal state before:
pp: 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)

Tactic:
show min (min (δ / 2) r) (B (n + 1)) ≤ B (n + 1)
      exact min_le_right _ _

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
⊢ ↑(v i) = ↑(0 i)

Tactic:
suffices ⟪(v i : E), v i⟫ = 0 by simpa only [inner_self_eq_zero] using! this

Goal state after:
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
⊢ ⟪↑(v i), ↑(v i)⟫ = 0
Module: Mathlib.Analysis.InnerProductSpace.Symmetric

Goal state before:
pp: case inr
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
T : E →ₗ[𝕜] E
hT : T.IsSymmetric
x y : E
h : I * I = -1
⊢ ⟪T x, y⟫ =
    (⟪T x, x⟫ + ⟪T x, y⟫ + (⟪T y, x⟫ + ⟪T y, y⟫) -
          (⟪T x, x⟫ - (⟪T x, y⟫ + (⟪T y, x⟫ - ⟪T y, y⟫)) +
            (I * ⟪T x, x⟫ + I * I * ⟪T x, y⟫ + (I * -I * ⟪T y, x⟫ + I * -I * I * ⟪T y, y⟫))) +
        (I * ⟪T x, x⟫ - (I * I * ⟪T x, y⟫ + (I * -I * ⟪T y, x⟫ - I * -I * I * ⟪T y, y⟫)))) /
      4

Tactic:
mul_neg,

Goal state after:
case inr
𝕜 : Type u_1
E : Type u_2
inst✝² : RCLike 𝕜
inst✝¹ : SeminormedAddCommGroup E
inst✝ : InnerProductSpace 𝕜 E
T : E →ₗ[𝕜] E
hT : T.IsSymmetric
x y : E
h : I * I = -1
⊢ ⟪T x, y⟫ =
    (⟪T x, x⟫ + ⟪T x, y⟫ + (⟪T y, x⟫ + ⟪T y, y⟫) -
          (⟪T x, x⟫ - (⟪T x, y⟫ + (⟪T y, x⟫ - ⟪T y, y⟫)) +
            (I * ⟪T x, x⟫ + I * I * ⟪T x, y⟫ + (-(I * I) * ⟪T y, x⟫ + -(I * I) * I * ⟪T y, y⟫))) +
        (I * ⟪T x, x⟫ - (I * I * ⟪T x, y⟫ + (-(I * I) * ⟪T y, x⟫ - -(I * I) * I * ⟪T y, y⟫)))) /
      4
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) Filter.atTop (nhds 0)

Tactic:
rw [← sub_self x]

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 (x - x))
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁵ : RCLike 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedAddCommGroup F
inst✝² : InnerProductSpace 𝕜 E
inst✝¹ : InnerProductSpace ℝ F
K : Submodule 𝕜 E
inst✝ : CompleteSpace ↥K
v : E
⊢ ∃ w ∈ K, v - w ∈ Kᗮ

Tactic:
rcases K.exists_norm_eq_iInf_of_complete_subspace (completeSpace_coe_iff_isComplete.mp ‹_›) v
      with ⟨w, hwK, hw⟩

Goal state after:
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁵ : RCLike 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedAddCommGroup F
inst✝² : InnerProductSpace 𝕜 E
inst✝¹ : InnerProductSpace ℝ F
K : Submodule 𝕜 E
inst✝ : CompleteSpace ↥K
v w : E
hwK : w ∈ K
hw : ‖v - w‖ = ⨅ w, ‖v - ↑w‖
⊢ ∃ w ∈ K, v - w ∈ Kᗮ
Module: Mathlib.Analysis.InnerProductSpace.Projection.Basic

Goal state before:
pp: case refine_2
𝕜 : Type u_1
inst✝⁶ : RCLike 𝕜
E : Type u_4
E' : Type u_5
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : InnerProductSpace 𝕜 E
inst✝² : InnerProductSpace 𝕜 E'
f : E →ₗᵢ[𝕜] E'
p : Submodule 𝕜 E
inst✝¹ : p.HasOrthogonalProjection
inst✝ : (map f.toLinearMap p).HasOrthogonalProjection
x : E
y : E'
hy : y ∈ map f.toLinearMap p
⊢ ⟪f x - f (p.starProjection x), y⟫ = 0

Tactic:
rcases hy with ⟨x', hx', rfl : f x' = y⟩

Goal state after:
case refine_2
𝕜 : Type u_1
inst✝⁶ : RCLike 𝕜
E : Type u_4
E' : Type u_5
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : InnerProductSpace 𝕜 E
inst✝² : InnerProductSpace 𝕜 E'
f : E →ₗᵢ[𝕜] E'
p : Submodule 𝕜 E
inst✝¹ : p.HasOrthogonalProjection
inst✝ : (map f.toLinearMap p).HasOrthogonalProjection
x x' : E
hx' : x' ∈ ↑p
⊢ ⟪f x - f (p.starProjection x), f x'⟫ = 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
v w : E
⊢ ↑(‖v‖ ^ 2) • (𝕜 ∙ v).starProjection w = ⟪v, w⟫ • v

Tactic:
suffices ((𝕜 ∙ v).starProjection (((‖v‖ : 𝕜) ^ 2) • w)) = ⟪v, w⟫ • v by
    simpa using this
  apply eq_starProjection_of_mem_of_inner_eq_zero
  · rw [Submodule.mem_span_singleton]
    use ⟪v, w⟫
  · rw [← Submodule.mem_orthogonal', Submodule.mem_orthogonal_singleton_iff_inner_left]
    simp [inner_sub_left, inner_smul_left, inner_self_eq_norm_sq_to_K, mul_comm]

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
⊢ ‖v‖ * ‖v‖ - ‖↑(K.orthogonalProjectionOnto v) - v‖ * ‖↑(K.orthogonalProjectionOnto v) - v‖ =
    ‖↑(K.orthogonalProjectionOnto v)‖ * ‖↑(K.orthogonalProjectionOnto v)‖ * 1

Tactic:
mul_one,

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
⊢ ‖v‖ * ‖v‖ - ‖↑(K.orthogonalProjectionOnto v) - v‖ * ‖↑(K.orthogonalProjectionOnto v) - v‖ =
    ‖↑(K.orthogonalProjectionOnto v)‖ * ‖↑(K.orthogonalProjectionOnto v)‖
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, f x = y ∧ ‖x‖ ≤ (2 * C + 1) * ‖y‖

Tactic:
have x_ineq : ‖x‖ ≤ (2 * C + 1) * ‖y‖ :=
    calc
      ‖x‖ ≤ ∑' n, ‖u n‖ := norm_tsum_le_tsum_norm sNu
      _ ≤ ∑' n, (1 / 2) ^ n * (C * ‖y‖) :=
        sNu.tsum_le_tsum ule <| Summable.mul_right _ summable_geometric_two
      _ = (∑' n, (1 / 2) ^ n) * (C * ‖y‖) := tsum_mul_right
      _ = 2 * C * ‖y‖ := by rw [tsum_geometric_two, mul_assoc]
      _ ≤ 2 * C * ‖y‖ + ‖y‖ := le_add_of_nonneg_right (norm_nonneg y)
      _ = (2 * C + 1) * ‖y‖ := by ring

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‖
⊢ ∃ x, f x = y ∧ ‖x‖ ≤ (2 * C + 1) * ‖y‖
Module: Mathlib.Analysis.InnerProductSpace.Projection.FiniteDimensional

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁷ : RCLike 𝕜
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedAddCommGroup F
inst✝⁴ : InnerProductSpace 𝕜 E
inst✝³ : InnerProductSpace ℝ F
K : Submodule 𝕜 E
ι : Type u_4
inst✝² : DecidableEq ι
inst✝¹ : Fintype ι
V : ι → Submodule 𝕜 E
inst✝ : ∀ (i : ι), CompleteSpace ↥(V i)
hV : OrthogonalFamily 𝕜 (fun i ↦ ↥(V i)) fun i ↦ (V i).subtypeₗᵢ
h : iSup V = ⊤
x : ⨁ (i : ι), ↥(V i)
⊢ (DFinsupp.equivFunOnFintype.symm fun i ↦ x i) = x

Tactic:
DFinsupp.equivFunOnFintype_symm_coe

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))
⊢ ∃ x, f x = y ∧ ‖x‖ ≤ (2 * C + 1) * ‖y‖

Tactic:
have L₂ : Tendsto (fun n => y - h^[n] y) atTop (𝓝 (y - 0)) := by
    refine tendsto_const_nhds.sub ?_
    rw [tendsto_iff_norm_sub_tendsto_zero]
    simp only [sub_zero]
    refine squeeze_zero (fun _ => norm_nonneg _) hnle ?_
    rw [← zero_mul ‖y‖]
    refine (_root_.tendsto_pow_atTop_nhds_zero_of_lt_one ?_ ?_).mul tendsto_const_nhds <;> norm_num

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))
⊢ ∃ x, f x = y ∧ ‖x‖ ≤ (2 * C + 1) * ‖y‖
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
⊢ ∑ j, star U₂ i✝.2 j.2 * star U₁ i✝.1 j.1 * U₁ j.1 j✝.1 * U₂ j.2 j✝.2 = 1 i✝ j✝

Tactic:
mul_assoc _ (star U₁ _ _),

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.2 * (star U₁ i✝.1 x.1 * U₁ x.1 j✝.1) * U₂ x.2 j✝.2 = 1 i✝ j✝
Module: Mathlib.Analysis.Normed.Operator.Banach

Goal state before:
pp: 𝕜 : Type u_1
𝕜' : Type u_2
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : NontriviallyNormedField 𝕜'
E : Type u_3
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
σ : 𝕜 →+* 𝕜'
σ' : 𝕜' →+* 𝕜
inst✝⁷ : RingHomInvPair σ σ'
F : Type u_4
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace 𝕜' F
inst✝⁴ : CompleteSpace E
inst✝³ : CompleteSpace F
inst✝² : RingHomInvPair σ' σ
inst✝¹ : RingHomIsometric σ
inst✝ : RingHomIsometric σ'
f : E →SL[σ] F
h : Bijective ⇑f
⊢ ∃ c, AntilipschitzWith c ⇑f

Tactic:
refine ⟨_, ContinuousLinearEquiv.ofBijective f ?_ ?_ |>.antilipschitz⟩

Goal state after:
case refine_1
𝕜 : Type u_1
𝕜' : Type u_2
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : NontriviallyNormedField 𝕜'
E : Type u_3
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
σ : 𝕜 →+* 𝕜'
σ' : 𝕜' →+* 𝕜
inst✝⁷ : RingHomInvPair σ σ'
F : Type u_4
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace 𝕜' F
inst✝⁴ : CompleteSpace E
inst✝³ : CompleteSpace F
inst✝² : RingHomInvPair σ' σ
inst✝¹ : RingHomIsometric σ
inst✝ : RingHomIsometric σ'
f : E →SL[σ] F
h : Bijective ⇑f
⊢ (↑f).ker = ⊥

case refine_2
𝕜 : Type u_1
𝕜' : Type u_2
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : NontriviallyNormedField 𝕜'
E : Type u_3
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
σ : 𝕜 →+* 𝕜'
σ' : 𝕜' →+* 𝕜
inst✝⁷ : RingHomInvPair σ σ'
F : Type u_4
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace 𝕜' F
inst✝⁴ : CompleteSpace E
inst✝³ : CompleteSpace F
inst✝² : RingHomInvPair σ' σ
inst✝¹ : RingHomIsometric σ
inst✝ : RingHomIsometric σ'
f : E →SL[σ] F
h : Bijective ⇑f
⊢ (↑f).range = ⊤
Module: Mathlib.MeasureTheory.Measure.Haar.OfBasis

Goal state before:
pp: ι : Type u_1
E : Type u_3
inst✝² : Fintype ι
inst✝¹ : AddCommGroup E
inst✝ : Module ℝ E
b : Basis ι ℝ E
x : E
⊢ (∃ t ∈ Icc 0 1, ∀ (i : ι), (b.repr x) i = ∑ x, (Finsupp.single x (t x * 1)) i) ↔ ∀ (i : ι), (b.repr x) i ∈ Icc 0 1

Tactic:
mul_one,

Goal state after:
ι : Type u_1
E : Type u_3
inst✝² : Fintype ι
inst✝¹ : AddCommGroup E
inst✝ : Module ℝ E
b : Basis ι ℝ E
x : E
⊢ (∃ t ∈ Icc 0 1, ∀ (i : ι), (b.repr x) i = ∑ x, (Finsupp.single x (t x)) i) ↔ ∀ (i : ι), (b.repr x) i ∈ Icc 0 1
Module: Mathlib.MeasureTheory.Measure.Lebesgue.Basic

Goal state before:
pp: a : ℝ
h : a ≠ 0
p q : ℚ
⊢ volume (Ioo ↑p ↑q) = (ofReal |a| • Measure.map (fun x ↦ a * x) volume) (Ioo ↑p ↑q)

Tactic:
rcases lt_or_gt_of_ne h with h | h

Goal state after:
case inl
a : ℝ
h✝ : a ≠ 0
p q : ℚ
h : a < 0
⊢ volume (Ioo ↑p ↑q) = (ofReal |a| • Measure.map (fun x ↦ a * x) volume) (Ioo ↑p ↑q)

case inr
a : ℝ
h✝ : a ≠ 0
p q : ℚ
h : 0 < a
⊢ volume (Ioo ↑p ↑q) = (ofReal |a| • Measure.map (fun x ↦ a * x) volume) (Ioo ↑p ↑q)
Module: Mathlib.MeasureTheory.Measure.Haar.OfBasis

Goal state before:
pp: ι : Type u_1
inst✝ : Fintype ι
b : OrthonormalBasis ι ℝ ℝ
⊢ ι ≃ Fin 1

Tactic:
apply Fintype.equivFinOfCardEq

Goal state after:
ι : Type u_1
inst✝ : Fintype ι
b : OrthonormalBasis ι ℝ ℝ
⊢ Fintype.card ι = 1
Module: Mathlib.MeasureTheory.Measure.Lebesgue.Basic

Goal state before:
pp: ι : Type u_1
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
t : TransvectionStruct ι ℝ
⊢ MeasurePreserving (⇑(toLin' t.toMatrix)) volume volume

Tactic:
have ht : Measurable (toLin' t.toMatrix) :=
    (toLin' t.toMatrix).continuous_of_finiteDimensional.measurable
  refine ⟨ht, ?_⟩
  refine (pi_eq fun s hs ↦ ?_).symm
  have h2s : MeasurableSet (univ.pi s) := .pi countable_univ fun i _ ↦ hs i
  simp_rw [← pi_pi, ← lintegral_indicator_one h2s]
  rw [lintegral_map (measurable_one.indicator h2s) ht, volume_pi]
  refine lintegral_eq_of_lmarginal_eq {t.i} ((measurable_one.indicator h2s).comp ht)
    (measurable_one.indicator h2s) ?_
  simp_rw [lmarginal_singleton]
  ext x
  cases t with | mk t_i t_j t_hij t_c =>
  simp [transvection, single_mulVec, t_hij.symm, ← Function.update_add,
    lintegral_add_right_eq_self fun xᵢ ↦ indicator (univ.pi s) 1 (Function.update x t_i xᵢ)]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Lebesgue.EqHaar

Goal state before:

Tactic:
∞ = ∑' _ : ℕ, μ s := (ENNReal.tsum_const_eq_top_of_ne_zero h).symm
    _ = ∑' n : ℕ, μ ({u n} + s) := by
      congr 1; ext1 n; simp only [image_add_left, measure_preimage_add, singleton_add]
    _ = μ (⋃ n, {u n} + s) := Eq.symm <| measure_iUnion hs fun n => by
      simpa only [image_add_left, singleton_add] using! measurable_id.const_add _ h's
    _ = μ (range u + s) := by rw [← iUnion_add, iUnion_singleton_eq_range]
    _ < ∞ := (hu.add sb).measure_lt_top

Goal state after: