mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Covering.Differentiation

Goal state before:

Tactic:
(q • μ) s = (q • μ) (s ∩ t ∪ s ∩ tᶜ) := by rw [inter_union_compl]
    _ ≤ (q • μ) (s ∩ t) + (q • μ) (s ∩ tᶜ) := measure_union_le _ _
    _ ≤ ρ (s ∩ t) + (q • μ) tᶜ := by gcongr; apply inter_subset_right
    _ = ρ (s ∩ t) := by simp [A]
    _ ≤ ρ s := by gcongr; apply inter_subset_left

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

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν ξ : Measure α
h : μ ⟂ₘ ξ
s : Set α := h.nullSet
hs : MeasurableSet s
h_le_s : μ.restrict s + (ν - ξ).restrict s = μ.restrict s + ν.restrict s - ξ.restrict s
h_le_s_compl : μ.restrict sᶜ + (ν - ξ).restrict sᶜ = μ.restrict sᶜ + ν.restrict sᶜ - ξ.restrict sᶜ
⊢ μ.restrict s + (ν - ξ).restrict s + (μ.restrict sᶜ + (ν - ξ).restrict sᶜ) =
    μ.restrict s + ν.restrict s - ξ.restrict s + (μ.restrict sᶜ + ν.restrict sᶜ - ξ.restrict sᶜ)

Tactic:
by rw [h_le_s, h_le_s_compl]

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

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν ξ : Measure α
h : μ ⟂ₘ ξ
⊢ μ + (ν - ξ) = μ + ν - ξ

Tactic:
let s := h.nullSet
  have hs : MeasurableSet s := h.measurableSet_nullSet
  have h_le_s : μ.restrict s + (ν - ξ).restrict s = μ.restrict s + ν.restrict s - ξ.restrict s := by
    rw [h.restrict_nullSet, restrict_sub_eq_restrict_sub_restrict hs]
    simp
  have h_le_s_compl : μ.restrict sᶜ + (ν - ξ).restrict sᶜ =
      μ.restrict sᶜ + ν.restrict sᶜ - ξ.restrict sᶜ := by
    rw [restrict_sub_eq_restrict_sub_restrict hs.compl, h.restrict_compl_nullSet]
    simp
  calc μ + (ν - ξ)
  _ = μ.restrict s + μ.restrict sᶜ + (ν - ξ).restrict s + (ν - ξ).restrict sᶜ := by
    rw [restrict_add_restrict_compl hs, add_assoc, restrict_add_restrict_compl hs]
  _ = μ.restrict s + (ν - ξ).restrict s + (μ.restrict sᶜ + (ν - ξ).restrict sᶜ) := by abel
  _ = (μ.restrict s + ν.restrict s - ξ.restrict s) +
      (μ.restrict sᶜ + ν.restrict sᶜ - ξ.restrict sᶜ) := by rw [h_le_s, h_le_s_compl]
  _ = (μ + ν - ξ).restrict s + (μ + ν - ξ).restrict sᶜ := by
      simp [restrict_sub_eq_restrict_sub_restrict hs,
        restrict_sub_eq_restrict_sub_restrict hs.compl]
  _ = μ + ν - ξ := by rw [restrict_add_restrict_compl hs]

Goal state after:
Module: Mathlib.MeasureTheory.Covering.Differentiation

Goal state before:
pp: α : Type u_1
inst✝⁴ : PseudoMetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
hρ : ρ ≪ μ
s : Set α
hs : MeasurableSet s
t : ℝ≥0
ht : 1 < t
t_ne_zero' : t ≠ 0
⊢ ↑t ≠ 0

Tactic:
simpa only [ENNReal.coe_eq_zero, Ne] using t_ne_zero'

Goal state after:
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Restrict

Goal state before:
pp: case pos
R : Type u_1
S : Type u_2
A : Type u_3
p q : A → Prop
inst✝²¹ : Semifield R
inst✝²⁰ : StarRing R
inst✝¹⁹ : MetricSpace R
inst✝¹⁸ : IsTopologicalSemiring R
inst✝¹⁷ : ContinuousStar R
inst✝¹⁶ : Semifield S
inst✝¹⁵ : StarRing S
inst✝¹⁴ : MetricSpace S
inst✝¹³ : IsTopologicalSemiring S
inst✝¹² : ContinuousStar S
inst✝¹¹ : Ring A
inst✝¹⁰ : StarRing A
inst✝⁹ : Algebra S A
inst✝⁸ : Algebra R S
inst✝⁷ : Algebra R A
inst✝⁶ : IsScalarTower R S A
inst✝⁵ : StarModule R S
inst✝⁴ : ContinuousSMul R S
inst✝³ : TopologicalSpace A
inst✝² : ContinuousFunctionalCalculus S A q
inst✝¹ : ContinuousFunctionalCalculus R A p
inst✝ : ContinuousMap.UniqueHom R A
f : C(S, R)
halg : IsClosedEmbedding ⇑(algebraMap R S)
a : A
hpa : p a
hqa : q a
h : SpectrumRestricts a ⇑f
g : R → R
hg : ContinuousOn g (spectrum R a)
⊢ cfc g a = cfc (fun x ↦ (algebraMap R S) (g (f x))) a

pp: case neg
R : Type u_1
S : Type u_2
A : Type u_3
p q : A → Prop
inst✝²¹ : Semifield R
inst✝²⁰ : StarRing R
inst✝¹⁹ : MetricSpace R
inst✝¹⁸ : IsTopologicalSemiring R
inst✝¹⁷ : ContinuousStar R
inst✝¹⁶ : Semifield S
inst✝¹⁵ : StarRing S
inst✝¹⁴ : MetricSpace S
inst✝¹³ : IsTopologicalSemiring S
inst✝¹² : ContinuousStar S
inst✝¹¹ : Ring A
inst✝¹⁰ : StarRing A
inst✝⁹ : Algebra S A
inst✝⁸ : Algebra R S
inst✝⁷ : Algebra R A
inst✝⁶ : IsScalarTower R S A
inst✝⁵ : StarModule R S
inst✝⁴ : ContinuousSMul R S
inst✝³ : TopologicalSpace A
inst✝² : ContinuousFunctionalCalculus S A q
inst✝¹ : ContinuousFunctionalCalculus R A p
inst✝ : ContinuousMap.UniqueHom R A
f : C(S, R)
halg : IsClosedEmbedding ⇑(algebraMap R S)
a : A
hpa : p a
hqa : q a
h : SpectrumRestricts a ⇑f
g : R → R
hg : ¬ContinuousOn g (spectrum R a)
⊢ cfc g a = cfc (fun x ↦ (algebraMap R S) (g (f x))) a

Tactic:
· rw [cfc_apply g a, cfcHom_eq_restrict f hpa hqa h, SpectrumRestricts.starAlgHom_apply,
      cfcHom_eq_cfc_extend 0]
    apply cfc_congr fun x hx ↦ ?_
    lift x to spectrum S a using hx
    simp [Function.comp]

Goal state after:
case neg
R : Type u_1
S : Type u_2
A : Type u_3
p q : A → Prop
inst✝²¹ : Semifield R
inst✝²⁰ : StarRing R
inst✝¹⁹ : MetricSpace R
inst✝¹⁸ : IsTopologicalSemiring R
inst✝¹⁷ : ContinuousStar R
inst✝¹⁶ : Semifield S
inst✝¹⁵ : StarRing S
inst✝¹⁴ : MetricSpace S
inst✝¹³ : IsTopologicalSemiring S
inst✝¹² : ContinuousStar S
inst✝¹¹ : Ring A
inst✝¹⁰ : StarRing A
inst✝⁹ : Algebra S A
inst✝⁸ : Algebra R S
inst✝⁷ : Algebra R A
inst✝⁶ : IsScalarTower R S A
inst✝⁵ : StarModule R S
inst✝⁴ : ContinuousSMul R S
inst✝³ : TopologicalSpace A
inst✝² : ContinuousFunctionalCalculus S A q
inst✝¹ : ContinuousFunctionalCalculus R A p
inst✝ : ContinuousMap.UniqueHom R A
f : C(S, R)
halg : IsClosedEmbedding ⇑(algebraMap R S)
a : A
hpa : p a
hqa : q a
h : SpectrumRestricts a ⇑f
g : R → R
hg : ¬ContinuousOn g (spectrum R a)
⊢ cfc g a = cfc (fun x ↦ (algebraMap R S) (g (f x))) a
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.NonUnital

Goal state before:
pp: R : Type u_1
A : Type u_2
p : A → Prop
inst✝¹¹ : CommSemiring R
inst✝¹⁰ : Nontrivial R
inst✝⁹ : StarRing R
inst✝⁸ : MetricSpace R
inst✝⁷ : IsTopologicalSemiring R
inst✝⁶ : ContinuousStar R
inst✝⁵ : NonUnitalRing A
inst✝⁴ : StarRing A
inst✝³ : TopologicalSpace A
inst✝² : Module R A
inst✝¹ : IsScalarTower R A A
inst✝ : SMulCommClass R A A
instCFCₙ : NonUnitalContinuousFunctionalCalculus R A p
f : R → R
a : A
hf : ContinuousOn f (σₙ R a)
hf0 : f 0 = 0
ha : p a
⊢ σₙ R (cfcₙ f a) = f '' σₙ R a

Tactic:
by
  simp [cfcₙ_apply f a, cfcₙHom_map_quasispectrum (p := p)]

Goal state after:
Module: Mathlib.RingTheory.Polynomial.Bernstein

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
n ν : ℕ
⊢ Polynomial.eval 0 (↑(n.choose ν) * X ^ ν * (1 - X) ^ (n - ν)) = if ν = 0 then 1 else 0

Tactic:
split_ifs with h

Goal state after:
case pos
R : Type u_1
inst✝ : CommRing R
n ν : ℕ
h : ν = 0
⊢ Polynomial.eval 0 (↑(n.choose ν) * X ^ ν * (1 - X) ^ (n - ν)) = 1

case neg
R : Type u_1
inst✝ : CommRing R
n ν : ℕ
h : ¬ν = 0
⊢ Polynomial.eval 0 (↑(n.choose ν) * X ^ ν * (1 - X) ^ (n - ν)) = 0
Module: Mathlib.RingTheory.Polynomial.Bernstein

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
n ν : ℕ
⊢ Polynomial.eval 1 (↑(n.choose ν) * X ^ ν * (1 - X) ^ (n - ν)) = if ν = n then 1 else 0

Tactic:
split_ifs with h

Goal state after:
case pos
R : Type u_1
inst✝ : CommRing R
n ν : ℕ
h : ν = n
⊢ Polynomial.eval 1 (↑(n.choose ν) * X ^ ν * (1 - X) ^ (n - ν)) = 1

case neg
R : Type u_1
inst✝ : CommRing R
n ν : ℕ
h : ¬ν = n
⊢ Polynomial.eval 1 (↑(n.choose ν) * X ^ ν * (1 - X) ^ (n - ν)) = 0
Module: Mathlib.RingTheory.Polynomial.Bernstein

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
n ν k : ℕ
w : k < n - ν
⊢ eval 1 ((⇑derivative)^[k] (bernsteinPolynomial R n ν)) = 0

Tactic:
flip' _ _ _ (tsub_pos_iff_lt.mp (pos_of_gt w)).le

Goal state after:
R : Type u_1
inst✝ : CommRing R
n ν k : ℕ
w : k < n - ν
⊢ eval 1 ((⇑derivative)^[k] ((bernsteinPolynomial R n (n - ν)).comp (1 - X))) = 0
Module: Mathlib.Topology.ContinuousMap.Polynomial

Goal state before:
pp: R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : IsTopologicalSemiring R
s : Set R
p : R[X]
⊢ (toContinuousMapOnAlgHom s) p ∈ R[(toContinuousMapOnAlgHom s) X]

Tactic:
refine p.induction_on (fun r => ?_) (fun f g hf hg => ?_) fun n r hn => ?_

Goal state after:
case refine_1
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : IsTopologicalSemiring R
s : Set R
p : R[X]
r : R
⊢ (toContinuousMapOnAlgHom s) (Polynomial.C r) ∈ R[(toContinuousMapOnAlgHom s) X]

case refine_2
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : IsTopologicalSemiring R
s : Set R
p f g : R[X]
hf : (toContinuousMapOnAlgHom s) f ∈ R[(toContinuousMapOnAlgHom s) X]
hg : (toContinuousMapOnAlgHom s) g ∈ R[(toContinuousMapOnAlgHom s) X]
⊢ (toContinuousMapOnAlgHom s) (f + g) ∈ R[(toContinuousMapOnAlgHom s) X]

case refine_3
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : IsTopologicalSemiring R
s : Set R
p : R[X]
n : ℕ
r : R
hn : (toContinuousMapOnAlgHom s) (Polynomial.C r * X ^ n) ∈ R[(toContinuousMapOnAlgHom s) X]
⊢ (toContinuousMapOnAlgHom s) (Polynomial.C r * X ^ (n + 1)) ∈ R[(toContinuousMapOnAlgHom s) X]
Module: Mathlib.RingTheory.Polynomial.Bernstein

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
n : ℕ
⊢ ∑ ν ∈ Finset.range (n + 1), bernsteinPolynomial R n ν = (X + (1 - X)) ^ n

Tactic:
by
      rw [add_pow]
      simp only [bernsteinPolynomial, mul_comm, mul_assoc]

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Bernstein

Goal state before:
pp: case hbc
E : Type u_1
inst✝⁵ : AddCommGroup E
inst✝⁴ : TopologicalSpace E
inst✝³ : IsTopologicalAddGroup E
inst✝² : Module ℝ E
inst✝¹ : ContinuousSMul ℝ E
inst✝ : LocallyConvexSpace ℝ E
f : C(↑I, E)
this✝ : UniformSpace E := IsTopologicalAddGroup.rightUniformSpace E
this : IsUniformAddGroup E
U : Set E
hU₀ : U ∈ 𝓝 0
hUc : Convex ℝ U
C : ℝ
hC : ∀ (x y : ↑I), gauge U (f x - f y) ≤ C
hC₀ : 0 ≤ C
δ : ℝ
hδ₀ : δ > 0
hδ : ∀ (x y : ↑I), dist x y < δ → gauge U (f x - f y) < 1 / 2
nhds_zero : Tendsto (fun n ↦ C / δ ^ 2 / ↑n) atTop (𝓝 0)
n : ℕ
nh : C / δ ^ 2 / ↑n < 1 / 2
hn₀ : n ≠ 0
x : ↑I
S : Finset (Fin (n + 1)) := {k | dist k/ₙ x < δ}
k : Fin (n + 1)
hk : k ∈ S
⊢ dist k/ₙ x < δ

Tactic:
simpa [S] using hk

Goal state after:
Module: Mathlib.Analysis.Normed.Algebra.Unitization

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
inst✝⁵ : NontriviallyNormedField 𝕜
inst✝⁴ : NonUnitalNormedRing A
inst✝³ : NormedSpace 𝕜 A
inst✝² : IsScalarTower 𝕜 A A
inst✝¹ : SMulCommClass 𝕜 A A
inst✝ : RegularNormedAlgebra 𝕜 A
⊢ ‖1‖ = 1

Tactic:
simpa only [norm_eq_sup, fst_one, norm_one, snd_one, map_one, map_zero,
      add_zero, sup_eq_left] using opNorm_le_bound _ zero_le_one fun x => by simp

Goal state after:
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: case right
X : Type u_2
inst✝ : TopologicalSpace X
A : Subalgebra ℝ C(X, ℝ)
hA : A.SeparatesPoints
f : C(X, ℝ)
K : Set X
hK : IsCompact K
ε : ℝ
pos : 0 < ε
restrict_on_K : C(X, ℝ) →⋆ₐ[ℝ] C(↑K, ℝ) := compStarAlgHom' ℝ ℝ { toFun := Subtype.val, continuous_toFun := ⋯ }
AK : Subalgebra ℝ C(↑K, ℝ) := Subalgebra.map (↑restrict_on_K) A
hsep : AK.SeparatesPoints
gK : C(↑K, ℝ)
hgKAK✝ : gK ∈ AK
hgapprox : ∀ (x : ↑K), ‖↑⟨gK, hgKAK✝⟩ x - K.domRestrict (⇑f) x‖ < ε
g : C(X, ℝ)
hgA : g ∈ A
hgKAK : ↑restrict_on_K g = gK
x : X
hxK : x ∈ K
eqg : g x = gK ⟨x, hxK⟩
⊢ ‖g x - f x‖ < ε

Tactic:
rw [eqg]

Goal state after:
case right
X : Type u_2
inst✝ : TopologicalSpace X
A : Subalgebra ℝ C(X, ℝ)
hA : A.SeparatesPoints
f : C(X, ℝ)
K : Set X
hK : IsCompact K
ε : ℝ
pos : 0 < ε
restrict_on_K : C(X, ℝ) →⋆ₐ[ℝ] C(↑K, ℝ) := compStarAlgHom' ℝ ℝ { toFun := Subtype.val, continuous_toFun := ⋯ }
AK : Subalgebra ℝ C(↑K, ℝ) := Subalgebra.map (↑restrict_on_K) A
hsep : AK.SeparatesPoints
gK : C(↑K, ℝ)
hgKAK✝ : gK ∈ AK
hgapprox : ∀ (x : ↑K), ‖↑⟨gK, hgKAK✝⟩ x - K.domRestrict (⇑f) x‖ < ε
g : C(X, ℝ)
hgA : g ∈ A
hgKAK : ↑restrict_on_K g = gK
x : X
hxK : x ∈ K
eqg : g x = gK ⟨x, hxK⟩
⊢ ‖gK ⟨x, hxK⟩ - f x‖ < ε
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Unique

Goal state before:
pp: X : Type u_1
inst✝⁶ : TopologicalSpace X
inst✝⁵ : Zero X
A : Type u_2
inst✝⁴ : NonUnitalRing A
inst✝³ : StarRing A
inst✝² : Module ℝ A
inst✝¹ : TopologicalSpace A
inst✝ : IsSemitopologicalRing A
φ : C(X, ℝ≥0)₀ →⋆ₙₐ[ℝ≥0] A
hφ : Continuous[_, inst✝¹] ⇑φ
⊢ Continuous[_, inst✝¹] ⇑φ.realContinuousMapZeroOfNNReal

Tactic:
dsimp [realContinuousMapZeroOfNNReal]

Goal state after:
X : Type u_1
inst✝⁶ : TopologicalSpace X
inst✝⁵ : Zero X
A : Type u_2
inst✝⁴ : NonUnitalRing A
inst✝³ : StarRing A
inst✝² : Module ℝ A
inst✝¹ : TopologicalSpace A
inst✝ : IsSemitopologicalRing A
φ : C(X, ℝ≥0)₀ →⋆ₙₐ[ℝ≥0] A
hφ : Continuous[_, inst✝¹] ⇑φ
⊢ Continuous[_, inst✝¹] fun f ↦ φ f.toNNReal - φ (-f).toNNReal
Module: Mathlib.Analysis.Normed.Algebra.UnitizationL1

Goal state before:
pp: case h₂
𝕜 : Type u_1
A : Type u_2
inst✝⁴ : NormedField 𝕜
inst✝³ : NonUnitalNormedRing A
inst✝² : NormedSpace 𝕜 A
inst✝¹ : IsScalarTower 𝕜 A A
inst✝ : SMulCommClass 𝕜 A A
x y : WithLp 1 (Unitization 𝕜 A)
⊢ ‖y.ofLp.toProd.1 • x.ofLp.toProd.2 + x.ofLp.toProd.2 * y.ofLp.toProd.2‖ ≤
    ‖x.ofLp.toProd.2‖ * ‖y.ofLp.toProd.1‖ + ‖x.ofLp.toProd.2‖ * ‖y.ofLp.toProd.2‖

Tactic:
· apply (norm_add_le _ _).trans
        gcongr
        · simp [norm_smul, mul_comm]
        · exact norm_mul_le _ _

Goal state after:
Module: Mathlib.Topology.Semicontinuity.Hemicontinuity

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
f : α → Set β
inst✝ : TopologicalSpace β
⊢ UpperHemicontinuous f ↔ ∀ (x : α), ∀ u ∈ 𝓝ˢ (f x), f ⁻¹' Iic u ∈ 𝓝 x

Tactic:
simp [upperHemicontinuous_iff, upperHemicontinuousAt_iff_preimage_Iic]

Goal state after:
Module: Mathlib.Topology.Sets.VietorisTopology

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
t : Set (Set (Set α))
ht₁ : t.Finite
ht₂ : t ⊆ powerset '' {U | IsOpen[inst✝] U} ∪ (fun V ↦ {s | (s ∩ V).Nonempty}) '' {V | IsOpen[inst✝] V}
s : Set α
hs : s ∈ ⋂₀ t
h✝ : s.Nonempty
⊢ ∃ u v,
    u ⊆ powerset '' {U | IsOpen[inst✝] U} ∧ v ⊆ (fun V ↦ {s | (s ∩ V).Nonempty}) '' {U | IsOpen[inst✝] U} ∧ u ∪ v = t

Tactic:
rw [← inter_eq_left, inter_union_distrib_left] at ht₂
      exact ⟨_, _, inter_subset_right, inter_subset_right, ht₂⟩

Goal state after:
Module: Mathlib.Topology.Semicontinuity.Hemicontinuity

Goal state before:
pp: α : Type u_3
β : Type u_4
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
f : α → Set β
ι : Type u_5
inst✝ : RegularSpace β
x₀ : α
l : Filter ι
hf : UpperHemicontinuousAt f x₀
hf_closed : IsClosed[inst✝¹] (f x₀)
x : ι → α
hx : Tendsto x l (𝓝 x₀)
y : ι → β
hy : ∃ᶠ (n : ι) in l, y n ∈ f (x n)
y₀ : β
hy₀ : Tendsto y l (𝓝 y₀)
this : y₀ ∉ f x₀
s : Set β
hs : s ∈ 𝓝ˢ (f x₀)
t : Set β
ht : t ∈ 𝓝 y₀
hst : Disjoint s t
⊢ ∀ᶠ (x_1 : ι) in l, y x_1 ∈ f (x x_1) → y x_1 ∈ s

Tactic:
filter_upwards [hx (hf s hs)] with n hn hyn

Goal state after:
α : Type u_3
β : Type u_4
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
f : α → Set β
ι : Type u_5
inst✝ : RegularSpace β
x₀ : α
l : Filter ι
hf : UpperHemicontinuousAt f x₀
hf_closed : IsClosed[inst✝¹] (f x₀)
x : ι → α
hx : Tendsto x l (𝓝 x₀)
y : ι → β
hy : ∃ᶠ (n : ι) in l, y n ∈ f (x n)
y₀ : β
hy₀ : Tendsto y l (𝓝 y₀)
this : y₀ ∉ f x₀
s : Set β
hs : s ∈ 𝓝ˢ (f x₀)
t : Set β
ht : t ∈ 𝓝 y₀
hst : Disjoint s t
n : ι
hn : n ∈ x ⁻¹' {x | s ∈ 𝓝ˢ (f x)}
hyn : y n ∈ f (x n)
⊢ y n ∈ s
Module: Mathlib.Topology.Semicontinuity.Hemicontinuity

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝ : TopologicalSpace α
f : α → Set β
b : β
⊢ (f ⁻¹' Iic {b}ᶜ)ᶜ = {x | b ∈ f x}

Tactic:
simp [Set.ext_iff, Iic, Set.mem_compl_iff]

Goal state after:
Module: Mathlib.Analysis.Normed.Algebra.Spectrum

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : NormedRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : HasSummableGeomSeries A
a : A
r : ℝ≥0
hr : ↑r < (↑‖a‖₊)⁻¹
n : ℕ
⊢ ‖ContinuousMultilinearMap.mkPiRing 𝕜 (Fin n) (a ^ n)‖₊ * r ^ n ≤ max 1 ‖1‖₊

Tactic:
← norm_toNNReal,

Goal state after:
𝕜 : Type u_1
A : Type u_2
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : NormedRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : HasSummableGeomSeries A
a : A
r : ℝ≥0
hr : ↑r < (↑‖a‖₊)⁻¹
n : ℕ
⊢ ‖ContinuousMultilinearMap.mkPiRing 𝕜 (Fin n) (a ^ n)‖.toNNReal * r ^ n ≤ max 1 ‖1‖₊
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: A : Type u_1
inst✝¹ : CStarAlgebra A
a : A
inst✝ : IsStarNormal a
n : ℕ
⊢ ↑‖(a⋆ * a) ^ n‖₊ ^ (1 / ↑n) = (↑‖a ^ n‖₊ ^ (1 / ↑n)) ^ ↑2

Tactic:
← rpow_mul,

Goal state after:
A : Type u_1
inst✝¹ : CStarAlgebra A
a : A
inst✝ : IsStarNormal a
n : ℕ
⊢ ↑‖(a⋆ * a) ^ n‖₊ ^ (1 / ↑n) = ↑‖a ^ n‖₊ ^ (1 / ↑n * ↑2)
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: F : Type u_1
A : Type u_2
inst✝¹ : CStarAlgebra A
inst✝ : FunLike F A ℂ
hF : AlgHomClass F ℂ A ℂ
φ : F
a : A
hsa : ∀ (s : ↥(selfAdjoint A)), (φ ↑s)⋆ = φ ↑s
⊢ φ (↑(ℜ a) + I • ↑(ℑ a))⋆ = (φ (↑(ℜ a) + I • ↑(ℑ a)))⋆

Tactic:
simp only [map_add, map_smul, star_add, star_smul, hsa, selfAdjoint.star_val_eq]

Goal state after:
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: F : Type u_1
A : Type u_2
inst✝¹ : CStarAlgebra A
inst✝ : FunLike F A ℂ
hF : AlgHomClass F ℂ A ℂ
φ : F
a : A
hsa : ∀ (s : ↥(selfAdjoint A)), (φ ↑s)⋆ = φ ↑s
⊢ φ a⋆ = (φ a)⋆

Tactic:
by
      rw [← realPart_add_I_smul_imaginaryPart a]
      simp only [map_add, map_smul, star_add, star_smul, hsa, selfAdjoint.star_val_eq]

Goal state after:
Module: Mathlib.Topology.ContinuousMap.ZeroAtInfty

Goal state before:
pp: F : Type u_1
α : Type u
β : Type v
γ : Type w
inst✝⁴ : TopologicalSpace α
inst✝³ : TopologicalSpace β
inst✝² : Zero β
inst✝¹ : FunLike F α β
inst✝ : ZeroAtInftyContinuousMapClass F α β
f g : α →C₀ β
h : (fun f ↦ f.toFun) f = (fun f ↦ f.toFun) g
⊢ f = g

Tactic:
obtain ⟨⟨_, _⟩, _⟩ := f
    obtain ⟨⟨_, _⟩, _⟩ := g
    congr

Goal state after:
Module: Mathlib.Topology.Sets.VietorisTopology

Goal state before:
pp: case refine_1
α : Type u_1
inst✝ : TopologicalSpace α
B : Set (Set α)
hB : IsTopologicalBasis B
⊢ ∀ ⦃x : Set (Set α)⦄, x ∈ {u | u.Finite ∧ u.Nonempty ∧ u ⊆ B} → IsOpen {K | ↑K ⊆ ⋃₀ x ∧ ∀ U ∈ x, (↑K ∩ U).Nonempty}

Tactic:
rintro u ⟨hu, -, huB⟩
    simp_rw [ofPred_and, ofPred_forall]
    exact .inter
      (isOpen_subsets_of_isOpen <| isOpen_sUnion fun U hU => hB.isOpen <| huB hU)
      (hu.isOpen_biInter fun U hU => isOpen_inter_nonempty_of_isOpen <| hB.isOpen <| huB hU)

Goal state after:
Module: Mathlib.Analysis.LocallyConvex.WeakDual

Goal state before:
pp: case mp
ι : Type u_4
𝕜 : Type u_5
E : Type u_6
inst✝⁵ : Finite ι
inst✝⁴ : Field 𝕜
t𝕜 : TopologicalSpace 𝕜
inst✝³ : IsTopologicalRing 𝕜
inst✝² : AddCommGroup E
inst✝¹ : Module 𝕜 E
inst✝ : T0Space 𝕜
f : ι → E →ₗ[𝕜] 𝕜
φ : E →ₗ[𝕜] 𝕜
x✝ : TopologicalSpace E := ⋯
⊢ φ ∈ Submodule.span 𝕜 (Set.range f) → Continuous[⨅ i, induced (⇑(f i)) t𝕜, t𝕜] ⇑φ

pp: case mpr
ι : Type u_4
𝕜 : Type u_5
E : Type u_6
inst✝⁵ : Finite ι
inst✝⁴ : Field 𝕜
t𝕜 : TopologicalSpace 𝕜
inst✝³ : IsTopologicalRing 𝕜
inst✝² : AddCommGroup E
inst✝¹ : Module 𝕜 E
inst✝ : T0Space 𝕜
f : ι → E →ₗ[𝕜] 𝕜
φ : E →ₗ[𝕜] 𝕜
x✝ : TopologicalSpace E := ⋯
⊢ Continuous[⨅ i, induced (⇑(f i)) t𝕜, t𝕜] ⇑φ → φ ∈ Submodule.span 𝕜 (Set.range f)

Tactic:
· exact Submodule.span_induction
      (Set.forall_mem_range.mpr fun i ↦ continuous_iInf_dom continuous_induced_dom) continuous_zero
      (fun _ _ _ _ ↦ .add) (fun c _ _ h ↦ h.const_smul c)

Goal state after:
case mpr
ι : Type u_4
𝕜 : Type u_5
E : Type u_6
inst✝⁵ : Finite ι
inst✝⁴ : Field 𝕜
t𝕜 : TopologicalSpace 𝕜
inst✝³ : IsTopologicalRing 𝕜
inst✝² : AddCommGroup E
inst✝¹ : Module 𝕜 E
inst✝ : T0Space 𝕜
f : ι → E →ₗ[𝕜] 𝕜
φ : E →ₗ[𝕜] 𝕜
x✝ : TopologicalSpace E := ⋯
⊢ Continuous[⨅ i, induced (⇑(f i)) t𝕜, t𝕜] ⇑φ → φ ∈ Submodule.span 𝕜 (Set.range f)
Module: Mathlib.Analysis.Normed.Operator.BanachSteinhaus

Goal state before:
pp: E : Type u_1
F : Type u_2
𝕜 : Type u_3
𝕜₂ : Type u_4
inst✝⁷ : SeminormedAddCommGroup E
inst✝⁶ : SeminormedAddCommGroup F
inst✝⁵ : NontriviallyNormedField 𝕜
inst✝⁴ : NontriviallyNormedField 𝕜₂
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedSpace 𝕜₂ F
σ₁₂ : 𝕜 →+* 𝕜₂
inst✝¹ : RingHomIsometric σ₁₂
ι : Type u_5
inst✝ : CompleteSpace E
g : ι → E →SL[σ₁₂] F
h : ∀ (x : E), ∃ C, ∀ (i : ι), ‖(g i) x‖ ≤ C
x✝ : Fin 1
x : E
⊢ BddAbove (range fun i ↦ (normSeminorm 𝕜₂ F) ((g i) x))

Tactic:
simpa [bddAbove_def, forall_mem_range] using h x

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case pos
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
c₁ c₂ : CU P
h : c₁.U ⊆ c₂.C
n₁ n₂ : ℕ
x : X
hx : x ∈ c₁.U
⊢ approx n₂ c₂ x ≤ approx n₁ c₁ x

pp: case neg
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
c₁ c₂ : CU P
h : c₁.U ⊆ c₂.C
n₁ n₂ : ℕ
x : X
hx : x ∉ c₁.U
⊢ approx n₂ c₂ x ≤ approx n₁ c₁ x

Tactic:
· calc
      approx n₂ c₂ x = 0 := approx_of_mem_C _ _ (h hx)
      _ ≤ approx n₁ c₁ x := approx_nonneg _ _ _

Goal state after:
case neg
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
c₁ c₂ : CU P
h : c₁.U ⊆ c₂.C
n₁ n₂ : ℕ
x : X
hx : x ∉ c₁.U
⊢ approx n₂ c₂ x ≤ approx n₁ c₁ x
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : NormalSpace X
s t : Set X
hs : IsClosed[inst✝¹] s
ht : IsClosed[inst✝¹] t
hd : Disjoint s t
⊢ ∃ f, EqOn (⇑f) 0 s ∧ EqOn (⇑f) 1 t ∧ ∀ (x : X), f x ∈ Icc 0 1

Tactic:
let P : Set X → Set X → Prop := fun _ _ ↦ True

Goal state after:
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : NormalSpace X
s t : Set X
hs : IsClosed[inst✝¹] s
ht : IsClosed[inst✝¹] t
hd : Disjoint s t
P : Set X → Set X → Prop := fun x x_1 ↦ True
⊢ ∃ f, EqOn (⇑f) 0 s ∧ EqOn (⇑f) 1 t ∧ ∀ (x : X), f x ∈ Icc 0 1
Module: Mathlib.Topology.ContinuousMap.Ideals

Goal state before:
pp: X : Type u_1
𝕜 : Type u_2
inst✝³ : TopologicalSpace X
inst✝² : CompactSpace X
inst✝¹ : T2Space X
inst✝ : RCLike 𝕜
⊢ Bijective ⇑(continuousMapEval X 𝕜)

Tactic:
refine ⟨fun x y hxy => ?_, fun φ => ?_⟩

Goal state after:
case refine_1
X : Type u_1
𝕜 : Type u_2
inst✝³ : TopologicalSpace X
inst✝² : CompactSpace X
inst✝¹ : T2Space X
inst✝ : RCLike 𝕜
x y : X
hxy : (continuousMapEval X 𝕜) x = (continuousMapEval X 𝕜) y
⊢ x = y

case refine_2
X : Type u_1
𝕜 : Type u_2
inst✝³ : TopologicalSpace X
inst✝² : CompactSpace X
inst✝¹ : T2Space X
inst✝ : RCLike 𝕜
φ : ↑(characterSpace 𝕜 C(X, 𝕜))
⊢ ∃ a, (continuousMapEval X 𝕜) a = φ
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case refine_5
X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : RegularSpace X
inst✝ : LocallyCompactSpace X
s t : Set X
hs : IsCompact s
h's : IsGδ s
ht : IsClosed[inst✝²] t
hd : Disjoint s t
U : ℕ → Set X
U_open : ∀ (n : ℕ), IsOpen[inst✝²] (U n)
hU : s = ⋂ n, U n
m : Set X
m_comp : IsCompact m
sm : s ⊆ interior m
mt : m ⊆ tᶜ
f : ℕ → C(X, ℝ)
fs : ∀ (n : ℕ), EqOn (⇑(f n)) 1 s
fm : ∀ (n : ℕ), EqOn (⇑(f n)) 0 (U n ∩ interior m)ᶜ
_hf : ∀ (n : ℕ), HasCompactSupport ⇑(f n)
f_range : ∀ (n : ℕ) (x : X), (f n) x ∈ Icc 0 1
u : ℕ → ℝ
u_pos : ∀ (i : ℕ), 0 < u i
u_sum : Summable u
hu : ∑' (i : ℕ), u i = 1
g : X → ℝ := fun x ↦ ∑' (n : ℕ), u n * (f n) x
hgmc : EqOn g 0 mᶜ
I : ∀ (n : ℕ) (x : X), u n * (f n) x ≤ u n
S : ∀ (x : X), Summable fun n ↦ u n * (f n) x
x : X
⊢ { toFun := g, continuous_toFun := ⋯ } x ≤ 1

Tactic:
apply le_trans _ hu.le

Goal state after:
X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : RegularSpace X
inst✝ : LocallyCompactSpace X
s t : Set X
hs : IsCompact s
h's : IsGδ s
ht : IsClosed[inst✝²] t
hd : Disjoint s t
U : ℕ → Set X
U_open : ∀ (n : ℕ), IsOpen[inst✝²] (U n)
hU : s = ⋂ n, U n
m : Set X
m_comp : IsCompact m
sm : s ⊆ interior m
mt : m ⊆ tᶜ
f : ℕ → C(X, ℝ)
fs : ∀ (n : ℕ), EqOn (⇑(f n)) 1 s
fm : ∀ (n : ℕ), EqOn (⇑(f n)) 0 (U n ∩ interior m)ᶜ
_hf : ∀ (n : ℕ), HasCompactSupport ⇑(f n)
f_range : ∀ (n : ℕ) (x : X), (f n) x ∈ Icc 0 1
u : ℕ → ℝ
u_pos : ∀ (i : ℕ), 0 < u i
u_sum : Summable u
hu : ∑' (i : ℕ), u i = 1
g : X → ℝ := ⋯
hgmc : EqOn g 0 mᶜ
I : ∀ (n : ℕ) (x : X), u n * (f n) x ≤ u n
S : ∀ (x : X), Summable fun n ↦ u n * (f n) x
x : X
⊢ { toFun := g, continuous_toFun := ⋯ } x ≤ ∑' (i : ℕ), u i