mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Geometry.Manifold.Immersion

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
H : Type u_7
inst✝³ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
n : ℕ∞ω
inst✝ : IsManifold I n M
x : M
y : E
hy : y ∈ ((chartAt H x).extend I).target
⊢ (↑((chartAt H x).extend I) ∘ id ∘ ↑((chartAt H x).extend I).symm) y =
    (⇑(ContinuousLinearEquiv.prodUnique 𝕜 E PUnit.{u_15 + 1}) ∘ fun x ↦ (x, 0)) y

Tactic:
have : I ((chartAt H x) ((chartAt H x).symm (I.symm y))) = y := by
    rw [(chartAt H x).right_inv (by simp_all), I.right_inv (by simp_all)]

Goal state after:
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
H : Type u_7
inst✝³ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
n : ℕ∞ω
inst✝ : IsManifold I n M
x : M
y : E
hy : y ∈ ((chartAt H x).extend I).target
this : ↑I (↑(chartAt H x) (↑(chartAt H x).symm (↑I.symm y))) = y
⊢ (↑((chartAt H x).extend I) ∘ id ∘ ↑((chartAt H x).extend I).symm) y =
    (⇑(ContinuousLinearEquiv.prodUnique 𝕜 E PUnit.{u_15 + 1}) ∘ fun x ↦ (x, 0)) y
Module: Mathlib.Geometry.Manifold.Immersion

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁹ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
H : Type u_7
inst✝⁶ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝⁵ : TopologicalSpace M
inst✝⁴ : ChartedSpace H M
n : ℕ∞ω
M' : Type u_15
inst✝³ : TopologicalSpace M'
inst✝² : ChartedSpace H M'
inst✝¹ : IsManifold I n M
inst✝ : IsManifold I n M'
x : M
y : E
hy : y ∈ ((chartAt H x).extend I).target
⊢ (↑((chartAt H (Sum.inl x)).extend I) ∘ Sum.inl ∘ ↑((chartAt H x).extend I).symm) y =
    (⇑(ContinuousLinearEquiv.prodUnique 𝕜 E Unit) ∘ fun x ↦ (x, 0)) y

Tactic:
have : I ((chartAt H x) ((chartAt H x).symm (I.symm y))) = y := by
    rw [(chartAt H x).right_inv (by simp_all), I.right_inv (by simp_all)]

Goal state after:
𝕜 : Type u_1
inst✝⁹ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
H : Type u_7
inst✝⁶ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝⁵ : TopologicalSpace M
inst✝⁴ : ChartedSpace H M
n : ℕ∞ω
M' : Type u_15
inst✝³ : TopologicalSpace M'
inst✝² : ChartedSpace H M'
inst✝¹ : IsManifold I n M
inst✝ : IsManifold I n M'
x : M
y : E
hy : y ∈ ((chartAt H x).extend I).target
this : ↑I (↑(chartAt H x) (↑(chartAt H x).symm (↑I.symm y))) = y
⊢ (↑((chartAt H (Sum.inl x)).extend I) ∘ Sum.inl ∘ ↑((chartAt H x).extend I).symm) y =
    (⇑(ContinuousLinearEquiv.prodUnique 𝕜 E Unit) ∘ fun x ↦ (x, 0)) y
Module: Mathlib.Geometry.Manifold.Immersion

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁹ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
H : Type u_7
inst✝⁶ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝⁵ : TopologicalSpace M
inst✝⁴ : ChartedSpace H M
n : ℕ∞ω
M' : Type u_15
inst✝³ : TopologicalSpace M'
inst✝² : ChartedSpace H M'
inst✝¹ : IsManifold I n M
inst✝ : IsManifold I n M'
x : M'
y : E
hy : y ∈ ((chartAt H x).extend I).target
⊢ (↑((chartAt H (Sum.inr x)).extend I) ∘ Sum.inr ∘ ↑((chartAt H x).extend I).symm) y =
    (⇑(ContinuousLinearEquiv.prodUnique 𝕜 E Unit) ∘ fun x ↦ (x, 0)) y

Tactic:
have : I ((chartAt H x) ((chartAt H x).symm (I.symm y))) = y := by
    rw [(chartAt H x).right_inv (by simp_all), I.right_inv (by simp_all)]

Goal state after:
𝕜 : Type u_1
inst✝⁹ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
H : Type u_7
inst✝⁶ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝⁵ : TopologicalSpace M
inst✝⁴ : ChartedSpace H M
n : ℕ∞ω
M' : Type u_15
inst✝³ : TopologicalSpace M'
inst✝² : ChartedSpace H M'
inst✝¹ : IsManifold I n M
inst✝ : IsManifold I n M'
x : M'
y : E
hy : y ∈ ((chartAt H x).extend I).target
this : ↑I (↑(chartAt H x) (↑(chartAt H x).symm (↑I.symm y))) = y
⊢ (↑((chartAt H (Sum.inr x)).extend I) ∘ Sum.inr ∘ ↑((chartAt H x).extend I).symm) y =
    (⇑(ContinuousLinearEquiv.prodUnique 𝕜 E Unit) ∘ fun x ↦ (x, 0)) y
Module: Mathlib.Geometry.Manifold.IntegralCurve.Basic

Goal state before:
pp: case mpr
E : Type u_1
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
H : Type u_2
inst✝² : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝¹ : TopologicalSpace M
inst✝ : ChartedSpace H M
γ : ℝ → M
v : (x : M) → TangentSpace I x
t₀ ε : ℝ
hε : ε > 0
h : IsMIntegralCurveOn γ v (Metric.ball t₀ ε)
⊢ ∃ s ∈ 𝓝 t₀, IsMIntegralCurveOn γ v s

Tactic:
exact ⟨Metric.ball t₀ ε, Metric.ball_mem_nhds _ hε, h⟩

Goal state after:
Module: Mathlib.Geometry.Manifold.IntegralCurve.Transform

Goal state before:
pp: E : Type u_1
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
H : Type u_2
inst✝² : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝¹ : TopologicalSpace M
inst✝ : ChartedSpace H M
v : (x : M) → TangentSpace I x
x : M
h : v x = 0
t : ℝ
⊢ HasMFDerivAt% (fun x_1 ↦ x) t (toSpanSingleton ℝ 0)

Tactic:
toSpanSingleton_zero

Goal state after:
E : Type u_1
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace ℝ E
H : Type u_2
inst✝² : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝¹ : TopologicalSpace M
inst✝ : ChartedSpace H M
v : (x : M) → TangentSpace I x
x : M
h : v x = 0
t : ℝ
⊢ HasMFDerivAt% (fun x_1 ↦ x) t 0
Module: Mathlib.Geometry.Manifold.VectorField.LieBracket

Goal state before:
pp: 𝕜 : Type u_1
inst✝¹⁴ : NontriviallyNormedField 𝕜
H : Type u_2
inst✝¹³ : TopologicalSpace H
E : Type u_3
inst✝¹² : NormedAddCommGroup E
inst✝¹¹ : NormedSpace 𝕜 E
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝¹⁰ : TopologicalSpace M
inst✝⁹ : ChartedSpace H M
H' : Type u_5
inst✝⁸ : TopologicalSpace H'
E' : Type u_6
inst✝⁷ : NormedAddCommGroup E'
inst✝⁶ : NormedSpace 𝕜 E'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝⁵ : TopologicalSpace M'
inst✝⁴ : ChartedSpace H' M'
inst✝³ : IsManifold I 2 M
inst✝² : IsManifold I' 2 M'
inst✝¹ : CompleteSpace E
inst✝ : CompleteSpace E'
f : M → M'
V W : (x : M') → TangentSpace I' x
x₀ : M
s : Set M
t : Set M'
hV : MDiffAt[t] (T% V) (f x₀)
hW : MDiffAt[t] (T% W) (f x₀)
hu : UniqueMDiff[s]
hf : ContMDiffOn I I' 2 f s
hx₀ : x₀ ∈ s
ht : t ⊆ (extChartAt I' (f x₀)).source
hst : MapsTo f s t
hsymm :
  IsSymmSndFDerivWithinAt 𝕜 (↑(extChartAt I' (f x₀)) ∘ f ∘ ↑(extChartAt I x₀).symm)
    (↑(extChartAt I x₀).symm ⁻¹' s ∩ range ↑I) (↑(extChartAt I x₀) x₀)
A : ↑(extChartAt I x₀).symm (↑(extChartAt I x₀) x₀) = x₀
A' : x₀ = ↑(extChartAt I x₀).symm (↑(extChartAt I x₀) x₀)
h'f : MDiffAt[s] f x₀
this : (mfderiv[range ↑I] ↑(extChartAt I x₀).symm (↑(extChartAt I x₀) x₀)).inverse = mfderiv% ↑(extChartAt I x₀) x₀
V' : (x : E') → TangentSpace 𝓘(𝕜, E') x := mpullbackWithin 𝓘(𝕜, E') I' (↑(extChartAt I' (f x₀)).symm) V (range ↑I')
hV' : V' = mpullbackWithin 𝓘(𝕜, E') I' (↑(extChartAt I' (f x₀)).symm) V (range ↑I')
W' : (x : E') → TangentSpace 𝓘(𝕜, E') x := mpullbackWithin 𝓘(𝕜, E') I' (↑(extChartAt I' (f x₀)).symm) W (range ↑I')
hW' : W' = mpullbackWithin 𝓘(𝕜, E') I' (↑(extChartAt I' (f x₀)).symm) W (range ↑I')
F : E → E' := (↑(extChartAt I' (f x₀)) ∘ f) ∘ ↑(extChartAt I x₀).symm
hF : F = (↑(extChartAt I' (f x₀)) ∘ f) ∘ ↑(extChartAt I x₀).symm
hFx₀ : ↑(extChartAt I' (f x₀)) (f x₀) = F (↑(extChartAt I x₀) x₀)
P :
  ∀ (Y : (x : M') → TangentSpace I' x),
    mpullbackWithin 𝓘(𝕜, E) I (↑(extChartAt I x₀).symm) (mpullbackWithin I I' f Y s)
        (range ↑I) =ᶠ[𝓝[↑(extChartAt I x₀).symm ⁻¹' s ∩ range ↑I] ↑(extChartAt I x₀) x₀]
      mpullbackWithin 𝓘(𝕜, E) 𝓘(𝕜, E') F (mpullbackWithin 𝓘(𝕜, E') I' (↑(extChartAt I' (f x₀)).symm) Y (range ↑I'))
        (↑(extChartAt I x₀).symm ⁻¹' s ∩ range ↑I)
⊢ ↑(extChartAt I x₀) x₀ ∈ ↑(extChartAt I x₀).symm ⁻¹' s ∩ range ↑I

Tactic:
by simp [hx₀]

Goal state after:
Module: Mathlib.Geometry.Manifold.IntegralCurve.ExistUnique

Goal state before:
pp: E : Type u_1
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
H : Type u_2
inst✝⁴ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝³ : TopologicalSpace M
inst✝² : ChartedSpace H M
inst✝¹ : IsManifold I 1 M
v : (x : M) → TangentSpace I x
t₀ : ℝ
x₀ : M
inst✝ : CompleteSpace E
hx : I.IsInteriorPoint x₀
left✝ : ContinuousAt (fun x ↦ ⟨x, v x⟩) x₀
hv :
  ContDiffWithinAt ℝ 1 (↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (range ↑I)
    (↑(extChartAt I x₀) x₀)
f : ℝ → E
hf1 : f t₀ = ↑(extChartAt I x₀) x₀
hf2 :
  ∀ᶠ (y : ℝ) in 𝓝 t₀,
    HasDerivAt f ((↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (f y)).2 y
a : ℝ
ha : a > 0
hf2' :
  ∀ y ∈ Metric.ball t₀ a,
    HasDerivAt f ((↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (f y)).2 y
hcont : ∀ A ∈ 𝓝 (↑(extChartAt I x₀) x₀), f ⁻¹' A ∈ 𝓝 t₀
hnhds : ∀ᶠ (x' : ℝ) in 𝓝 t₀, f ⁻¹' interior (extChartAt I x₀).target ∈ 𝓝 x'
s : Set ℝ
hs : s ∈ 𝓝 t₀
haux :
  ∀ y ∈ s,
    HasDerivAt f ((↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (f y)).2 y ∧
      f ⁻¹' interior (extChartAt I x₀).target ∈ 𝓝 y
t : ℝ
ht : t ∈ s
xₜ : M := ↑(extChartAt I x₀).symm (f t)
h : HasDerivAt f ((tangentCoordChange I xₜ x₀ xₜ) (v xₜ)) t
⊢ HasMFDerivAt[s] (↑(extChartAt I x₀).symm ∘ f) t
    (ContinuousLinearMap.smulRight 1 (v ((↑(extChartAt I x₀).symm ∘ f) t)))

Tactic:
have hf3 := mem_preimage.mp <| mem_of_mem_nhds (haux t ht).2

Goal state after:
E : Type u_1
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
H : Type u_2
inst✝⁴ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝³ : TopologicalSpace M
inst✝² : ChartedSpace H M
inst✝¹ : IsManifold I 1 M
v : (x : M) → TangentSpace I x
t₀ : ℝ
x₀ : M
inst✝ : CompleteSpace E
hx : I.IsInteriorPoint x₀
left✝ : ContinuousAt (fun x ↦ ⟨x, v x⟩) x₀
hv :
  ContDiffWithinAt ℝ 1 (↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (range ↑I)
    (↑(extChartAt I x₀) x₀)
f : ℝ → E
hf1 : f t₀ = ↑(extChartAt I x₀) x₀
hf2 :
  ∀ᶠ (y : ℝ) in 𝓝 t₀,
    HasDerivAt f ((↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (f y)).2 y
a : ℝ
ha : a > 0
hf2' :
  ∀ y ∈ Metric.ball t₀ a,
    HasDerivAt f ((↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (f y)).2 y
hcont : ∀ A ∈ 𝓝 (↑(extChartAt I x₀) x₀), f ⁻¹' A ∈ 𝓝 t₀
hnhds : ∀ᶠ (x' : ℝ) in 𝓝 t₀, f ⁻¹' interior (extChartAt I x₀).target ∈ 𝓝 x'
s : Set ℝ
hs : s ∈ 𝓝 t₀
haux :
  ∀ y ∈ s,
    HasDerivAt f ((↑(extChartAt I.tangent ⟨x₀, v x₀⟩) ∘ (fun x ↦ ⟨x, v x⟩) ∘ ↑(extChartAt I x₀).symm) (f y)).2 y ∧
      f ⁻¹' interior (extChartAt I x₀).target ∈ 𝓝 y
t : ℝ
ht : t ∈ s
xₜ : M := ↑(extChartAt I x₀).symm (f t)
h : HasDerivAt f ((tangentCoordChange I xₜ x₀ xₜ) (v xₜ)) t
hf3 : f t ∈ interior (extChartAt I x₀).target
⊢ HasMFDerivAt[s] (↑(extChartAt I x₀).symm ∘ f) t
    (ContinuousLinearMap.smulRight 1 (v ((↑(extChartAt I x₀).symm ∘ f) t)))
Module: Mathlib.Geometry.Manifold.IntegralCurve.ExistUnique

Goal state before:
pp: case refine_2
E : Type u_1
inst✝⁷ : NormedAddCommGroup E
inst✝⁶ : NormedSpace ℝ E
H : Type u_2
inst✝⁵ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace H M
inst✝² : IsManifold I 1 M
γ : ℝ → M
v : (x : M) → TangentSpace I x
inst✝¹ : T2Space M
inst✝ : BoundarylessManifold I M
hγ : IsMIntegralCurve γ v
hv : ContMDiff I I.tangent 1 fun x ↦ ⟨x, v x⟩
a b : ℝ
heq : γ a = γ b
hne : a ≠ b
⊢ Periodic γ |a - b|

Tactic:
· by_cases! hab : a - b < 0
    · rw [abs_of_neg hab, neg_sub]
      exact hγ.periodic_of_eq hv heq.symm
    · rw [abs_of_nonneg hab]
      exact hγ.periodic_of_eq hv heq

Goal state after:
Module: Mathlib.Geometry.Manifold.Riemannian.PathELength

Goal state before:
pp: case refine_2
E : Type u_1
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
H : Type u_2
inst✝⁴ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_3
inst✝³ : TopologicalSpace M
inst✝² : ChartedSpace H M
inst✝¹ : (x : M) → ENorm (TangentSpace I x)
inst✝ : ∀ (x : M), ENormSMulClass ℝ (TangentSpace I x)
x y : M
r : ℝ≥0∞
a b : ℝ
hr : riemannianEDist I x y < r
hab : a < b
γ : ℝ → M
hγx : γ 0 = x
hγy : γ 1 = y
γ_smooth : ContMDiffOn 𝓘(ℝ, ℝ) I 1 γ (Icc 0 1)
hγ : pathELength I γ 0 1 < r
a' : ℝ
haa' : a < a'
ha'b : a' < b
b' : ℝ
ha'b' : a' < b'
hb'b : b' < b
η : ℝ → ℝ := fun t ↦ ((b' - a')⁻¹ * (t - a')).smoothTransition
A : ∀ t < a', η t = 0
A' : ∀ t < a', (γ ∘ η) t = x
B : ∀ (t : ℝ), b' < t → η t = 1
B' : ∀ (t : ℝ), b' < t → (γ ∘ η) t = y
⊢ pathELength I (γ ∘ η) a b < r

Tactic:
convert! hγ using 1
    rw [← A a haa', ← B b hb'b]
    apply pathELength_comp_of_monotoneOn hab.le
    · apply Monotone.monotoneOn
      apply Real.smoothTransition.monotone.comp
      intro t u htu
      dsimp only
      gcongr
    · simp only [η]
      apply (ContDiff.contDiffOn _).differentiableOn one_ne_zero
      fun_prop
    · rw [A a haa', B b hb'b]
      apply γ_smooth.mdifferentiableOn one_ne_zero

Goal state after:
Module: Mathlib.Geometry.Manifold.Submersion

Goal state before:
pp: 𝕜 : Type u_1
H : Type u_7
E : Type u
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
n : ℕ∞ω
inst✝ : IsManifold I n M
x : M
y : E
hy : y ∈ ((chartAt H x).extend I).target
⊢ (↑((chartAt H x).extend I) ∘ id ∘ ↑((chartAt H x).extend I).symm) y =
    (Prod.fst ∘ ⇑(ContinuousLinearEquiv.prodUnique 𝕜 E PUnit.{u_15 + 1}).symm) y

Tactic:
have : I ((chartAt H x) ((chartAt H x).symm (I.symm y))) = y := by
    rw [(chartAt H x).right_inv (by simp_all), I.right_inv (by simp_all)]

Goal state after:
𝕜 : Type u_1
H : Type u_7
E : Type u
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_11
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
n : ℕ∞ω
inst✝ : IsManifold I n M
x : M
y : E
hy : y ∈ ((chartAt H x).extend I).target
this : ↑I (↑(chartAt H x) (↑(chartAt H x).symm (↑I.symm y))) = y
⊢ (↑((chartAt H x).extend I) ∘ id ∘ ↑((chartAt H x).extend I).symm) y =
    (Prod.fst ∘ ⇑(ContinuousLinearEquiv.prodUnique 𝕜 E PUnit.{u_15 + 1}).symm) y
Module: Mathlib.Geometry.Manifold.VectorBundle.Tensoriality

Goal state before:
pp: 𝕜 : Type u_1
inst✝¹⁴ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹³ : NormedAddCommGroup E
inst✝¹² : NormedSpace 𝕜 E
H : Type u_3
inst✝¹¹ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝¹⁰ : TopologicalSpace M
inst✝⁹ : ChartedSpace H M
F : Type u_5
inst✝⁸ : NormedAddCommGroup F
inst✝⁷ : NormedSpace 𝕜 F
V : M → Type u_6
inst✝⁶ : TopologicalSpace (TotalSpace F V)
inst✝⁵ : (x : M) → AddCommGroup (V x)
inst✝⁴ : (x : M) → Module 𝕜 (V x)
inst✝³ : (x : M) → TopologicalSpace (V x)
inst✝² : FiberBundle F V
A : Type u_9
inst✝¹ : AddCommGroup A
inst✝ : Module 𝕜 A
Φ : ((x : M) → V x) → A
x : M
hΦ : TensorialAt I F Φ x
σ σ' : (x : M) → V x
hσ : MDiffAt (T% σ) x
hσ' : MDiffAt (T% σ') x
hσσ' : ∀ᶠ (x' : M) in 𝓝 x, σ x' = σ' x'
ψ : M → 𝕜 := fun x' ↦ if σ x' = σ' x' then 1 else 0
hψx : ψ x = 1
this : ∀ (x' : M), (ψ • σ) x' = (ψ • σ') x'
⊢ Φ σ = Φ σ'

Tactic:
have hψ' : MDiffAt ψ x := by
    have : MDiffAt (fun (_x : M) ↦ (1 : 𝕜)) x := mdifferentiableAt_const
    exact this.congr_of_eventuallyEq (hσσ'.mono fun x' hx' ↦ by simp [ψ, hx'])

Goal state after:
𝕜 : Type u_1
inst✝¹⁴ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹³ : NormedAddCommGroup E
inst✝¹² : NormedSpace 𝕜 E
H : Type u_3
inst✝¹¹ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝¹⁰ : TopologicalSpace M
inst✝⁹ : ChartedSpace H M
F : Type u_5
inst✝⁸ : NormedAddCommGroup F
inst✝⁷ : NormedSpace 𝕜 F
V : M → Type u_6
inst✝⁶ : TopologicalSpace (TotalSpace F V)
inst✝⁵ : (x : M) → AddCommGroup (V x)
inst✝⁴ : (x : M) → Module 𝕜 (V x)
inst✝³ : (x : M) → TopologicalSpace (V x)
inst✝² : FiberBundle F V
A : Type u_9
inst✝¹ : AddCommGroup A
inst✝ : Module 𝕜 A
Φ : ((x : M) → V x) → A
x : M
hΦ : TensorialAt I F Φ x
σ σ' : (x : M) → V x
hσ : MDiffAt (T% σ) x
hσ' : MDiffAt (T% σ') x
hσσ' : ∀ᶠ (x' : M) in 𝓝 x, σ x' = σ' x'
ψ : M → 𝕜 := fun x' ↦ if σ x' = σ' x' then 1 else 0
hψx : ψ x = 1
this : ∀ (x' : M), (ψ • σ) x' = (ψ • σ') x'
hψ' : MDiffAt ψ x
⊢ Φ σ = Φ σ'
Module: Mathlib.GroupTheory.GroupAction.CardCommute

Goal state before:
pp: case inl
G : Type u_3
inst✝ : Group G
val✝ : Fintype G
⊢ card { p // Commute p.1 p.2 } = card (ConjClasses G) * card G

Tactic:
calc card { p : G × G // Commute p.1 p.2 }
      _ = card ((a : G) × { b // Commute a b }) :=
            card_congr (Equiv.subtypeProdEquivSigmaSubtype Commute)
      _ = ∑ i, card { b // Commute i b } := card_sigma
      _ = ∑ x, card (MulAction.fixedBy G x) :=
            sum_equiv ConjAct.toConjAct.toEquiv (fun a ↦ card { b // Commute a b })
              (fun g ↦ card (MulAction.fixedBy G g))
              fun g ↦ card_congr' <| congr_arg _ <| funext fun h ↦ mul_inv_eq_iff_eq_mul.symm.eq
      _ = card (Quotient (MulAction.orbitRel (ConjAct G) G)) * card (ConjAct G) :=
             MulAction.sum_card_fixedBy_eq_card_orbits_mul_card_group _ _
      _ = card (ConjClasses G) * card G := by
             congr 1; apply card_congr'; congr; ext
             exact (Setoid.comm' _).trans isConj_iff.symm

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.Dihedral

Goal state before:
pp: case neg
n : ℕ
h1 : n ≠ 1
h : IsCyclic (DihedralGroup n)
h2 : ¬n = 2
⊢ False

Tactic:
· exact not_commutative h1 h2 h.isMulCommutative

Goal state after:
Module: Mathlib.GroupTheory.Coprod.Basic

Goal state before:
pp: M : Type u_1
N : Type u_2
inst✝¹ : MulOneClass M
inst✝ : MulOneClass N
motive : M ∗ N → Prop
one : motive 1
inl_mul : ∀ (m : M) (x : M ∗ N), motive x → motive (inl m * x)
inr_mul : ∀ (n : N) (x : M ∗ N), motive x → motive (inr n * x)
x : FreeMonoid (M ⊕ N)
⊢ motive (mk x)

Tactic:
induction x using FreeMonoid.inductionOn' with
  | one => exact one
  | of_mul x xs ih =>
    cases x with
    | inl m => simpa using inl_mul m _ ih
    | inr n => simpa using inr_mul n _ ih

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Basic

Goal state before:
pp: case inr
B : Type u_1
W : Type u_3
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i i' : B
m : ℕ
k : ℤ
this✝ : ¬Even (2 * k + 1)
this : ¬Even (↑(M.M i i') * 2 - (2 * k + 1))
⊢ cs.simple i' * (cs.simple i * cs.simple i') ^ (1 / 2 + k) =
    cs.simple i * (cs.simple i' * cs.simple i) ^ (-1 / 2 + (-k + ↑(M.M i i')))

Tactic:
simp [zpow_add, simple_mul_simple_pow', ← inv_zpow, ← mul_assoc]

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Basic

Goal state before:
pp: B : Type u_1
W : Type u_3
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i i' : B
this : cs.wordProd (alternatingWord i i' (M.M i i')) = cs.wordProd (alternatingWord i' i (M.M i i'))
⊢ cs.wordProd (braidWord M i i') = cs.wordProd (braidWord M i' i)

Tactic:
nth_rw 2 [M.symmetric i i'] at this

Goal state after:
B : Type u_1
W : Type u_3
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i i' : B
this : cs.wordProd (alternatingWord i i' (M.M i i')) = cs.wordProd (alternatingWord i' i (M.M i' i))
⊢ cs.wordProd (braidWord M i i') = cs.wordProd (braidWord M i' i)
Module: Mathlib.GroupTheory.Coxeter.Basic

Goal state before:
pp: B : Type u_1
W : Type u_3
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i i' : B
this : cs.wordProd (alternatingWord i i' (M.M i i')) = cs.wordProd (alternatingWord i' i (M.M i' i))
⊢ cs.wordProd (braidWord M i i') = cs.wordProd (braidWord M i' i)

Tactic:
exact this

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: case mp
B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
w t : W
⊢ cs.IsReflection (w * t * w⁻¹) → cs.IsReflection t

Tactic:
intro h
    simpa [← mul_assoc] using h.conj w⁻¹

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Length

Goal state before:
pp: case mp
B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i : B
hω : cs.IsReduced [i]
h : cs.length (cs.wordProd [i]) = 1
⊢ ∃ i_1, cs.wordProd [i] = cs.simple i_1

Tactic:
exact ⟨i, cs.wordProd_singleton i⟩

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
t : W
ht : cs.IsReflection t
w : W
⊢ cs.IsLeftInversion (t * w) t ↔ ¬cs.IsLeftInversion w t

Tactic:
rw [← isRightInversion_inv_iff, ← isRightInversion_inv_iff, mul_inv_rev, ht.inv,
    ht.isRightInversion_mul_left_iff]

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
j : ℕ
h : j < ω.length
⊢ (cs.rightInvSeq ω)[j] =
    (cs.wordProd (drop (j + 1) ω))⁻¹ * (Option.map cs.simple ω[j]?).getD 1 * cs.wordProd (drop (j + 1) ω)

Tactic:
by
  rw [← List.getD_eq_getElem (ris ω) 1, getD_rightInvSeq]

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
t : W
ht : t ∈ cs.leftInvSeq ω
⊢ cs.IsReflection t

Tactic:
by
  simp only [leftInvSeq_eq_reverse_rightInvSeq_reverse, mem_reverse] at ht
  exact cs.isReflection_of_mem_rightInvSeq ω.reverse ht

Goal state after:
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
j : ℕ
⊢ cs.wordProd ω *
      ((cs.wordProd (drop (j + 1) ω))⁻¹ * (Option.map cs.simple ω[j]?).getD 1 * cs.wordProd (drop (j + 1) ω)) =
    cs.wordProd (ω.eraseIdx j)

Tactic:
eraseIdx_eq_take_drop_succ

Goal state after:
B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
j : ℕ
⊢ cs.wordProd ω *
      ((cs.wordProd (drop (j + 1) ω))⁻¹ * (Option.map cs.simple ω[j]?).getD 1 * cs.wordProd (drop (j + 1) ω)) =
    cs.wordProd (take j ω ++ drop (j + 1) ω)
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
j : ℕ
⊢ cs.wordProd (take j ω) * (Option.map cs.simple ω[j]?).getD 1 * (cs.wordProd (take j ω))⁻¹ * cs.wordProd ω =
    cs.wordProd (ω.eraseIdx j)

Tactic:
eraseIdx_eq_take_drop_succ

Goal state after:
B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
j : ℕ
⊢ cs.wordProd (take j ω) * (Option.map cs.simple ω[j]?).getD 1 * (cs.wordProd (take j ω))⁻¹ * cs.wordProd ω =
    cs.wordProd (take j ω ++ drop (j + 1) ω)
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
rω : cs.IsReduced ω
j j' : ℕ
j_lt_j' : j < j'
j'_lt_length : j' < ω.length
dup : some (cs.rightInvSeq ω)[j] = some (cs.rightInvSeq ω)[j']
⊢ False

Tactic:
apply Option.some_injective at dup

Goal state after:
B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
ω : List B
rω : cs.IsReduced ω
j j' : ℕ
j_lt_j' : j < j'
j'_lt_length : j' < ω.length
dup : (cs.rightInvSeq ω)[j] = (cs.rightInvSeq ω)[j']
⊢ False
Module: Mathlib.GroupTheory.Coxeter.Inversion

Goal state before:
pp: B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i j : B
p k : ℕ
h : k + 1 < 2 * p
⊢ cs.simple (alternatingWord i j (2 * p))[k + 1] = cs.simple (alternatingWord j i (2 * p))[k]

Tactic:
rw [getElem_alternatingWord_swapIndices i j (2 * p) k]

Goal state after:
B : Type u_1
W : Type u_2
inst✝ : Group W
M : CoxeterMatrix B
cs : CoxeterSystem M W
i j : B
p k : ℕ
h : k + 1 < 2 * p
⊢ k + 1 < 2 * p