mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.Inner.PushoutProduct

Goal state before:
pp: X₁ X₂ Y₁ Y₂ : SSet
i : X₁ ⟶ Y₁
j : X₂ ⟶ Y₂
sq₁₂ : (curriedTensor SSet).PushoutObjObj i j
inst✝ : Mono i
hj : innerAnodyneExtensions j
E B : SSet
p : E ⟶ B
⊢ innerFibrations p → HasLiftingProperty sq₁₂.ι p

Tactic:
hp

Goal state after:
X₁ X₂ Y₁ Y₂ : SSet
i : X₁ ⟶ Y₁
j : X₂ ⟶ Y₂
sq₁₂ : (curriedTensor SSet).PushoutObjObj i j
inst✝ : Mono i
hj : innerAnodyneExtensions j
E B : SSet
p : E ⟶ B
hp : innerFibrations p
⊢ HasLiftingProperty sq₁₂.ι p
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.PushoutProduct

Goal state before:
pp: X₁ Y₁ E✝ B✝ : SSet
i : X₁ ⟶ Y₁
p✝ : E✝ ⟶ B✝
inst✝¹ : Mono i
inst✝ : Fibration p✝
sq₁₃ : internalHom.PullbackObjObj i p✝
m : ℕ
X Y : SSet
k : Fin (m + 2)
sq₁₂ : (curriedTensor SSet).PushoutObjObj i Λ[m + 1, k].ι :=
  Functor.PushoutObjObj.ofHasPushout (curriedTensor SSet) i Λ[m + 1, k].ι
E B : SSet
p : E ⟶ B
⊢ fibrations SSet p → HasLiftingProperty sq₁₂.ι p

Tactic:
hp

Goal state after:
X₁ Y₁ E✝ B✝ : SSet
i : X₁ ⟶ Y₁
p✝ : E✝ ⟶ B✝
inst✝¹ : Mono i
inst✝ : Fibration p✝
sq₁₃ : internalHom.PullbackObjObj i p✝
m : ℕ
X Y : SSet
k : Fin (m + 2)
sq₁₂ : (curriedTensor SSet).PushoutObjObj i Λ[m + 1, k].ι :=
  Functor.PushoutObjObj.ofHasPushout (curriedTensor SSet) i Λ[m + 1, k].ι
E B : SSet
p : E ⟶ B
hp : fibrations SSet p
⊢ HasLiftingProperty sq₁₂.ι p
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.PushoutProduct

Goal state before:
pp: X₁ X₂ Y₁ Y₂ : SSet
i : X₁ ⟶ Y₁
j : X₂ ⟶ Y₂
sq₁₂ : (curriedTensor SSet).PushoutObjObj i j
inst✝ : Mono i
hj : anodyneExtensions j
E B : SSet
p : E ⟶ B
⊢ fibrations SSet p → HasLiftingProperty sq₁₂.ι p

Tactic:
hp

Goal state after:
X₁ X₂ Y₁ Y₂ : SSet
i : X₁ ⟶ Y₁
j : X₂ ⟶ Y₂
sq₁₂ : (curriedTensor SSet).PushoutObjObj i j
inst✝ : Mono i
hj : anodyneExtensions j
E B : SSet
p : E ⟶ B
hp : fibrations SSet p
⊢ HasLiftingProperty sq₁₂.ι p
Module: Mathlib.AlgebraicTopology.SimplicialSet.CoherentIso

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
F : WalkingIso ⥤ C
⊢ ∀ (X : WalkingIso), ((fun p ↦ fromIso p.snd.snd) ((fun F ↦ ⟨F.obj zero, ⟨F.obj one, toIso F⟩⟩) F)).obj X = F.obj X

Tactic:
rintro (_ | _)

Goal state after:
case false
C : Type u
inst✝ : Category.{v, u} C
F : WalkingIso ⥤ C
⊢ ((fun p ↦ fromIso p.snd.snd) ((fun F ↦ ⟨F.obj zero, ⟨F.obj one, toIso F⟩⟩) F)).obj { as := { down := false } } =
    F.obj { as := { down := false } }

case true
C : Type u
inst✝ : Category.{v, u} C
F : WalkingIso ⥤ C
⊢ ((fun p ↦ fromIso p.snd.snd) ((fun F ↦ ⟨F.obj zero, ⟨F.obj one, toIso F⟩⟩) F)).obj { as := { down := true } } =
    F.obj { as := { down := true } }
Module: Mathlib.AlgebraicTopology.SimplicialSet.CoherentIso

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
F : WalkingIso ⥤ C
⊢ ∀ (X : WalkingIso), ((fun p ↦ fromIso p.snd.snd) ((fun F ↦ ⟨F.obj zero, ⟨F.obj one, toIso F⟩⟩) F)).obj X = F.obj X

Tactic:
rintro (_ | _) <;> rfl

Goal state after:
Module: Mathlib.Analysis.AbsoluteValue.Equivalence

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁷ : Field R
inst✝⁶ : Field S
inst✝⁵ : LinearOrder S
inst✝⁴ : TopologicalSpace S
inst✝³ : IsStrictOrderedRing S
inst✝² : Archimedean S
inst✝¹ : OrderTopology S
ι : Type u_3
inst✝ : Finite ι
v : ι → AbsoluteValue R S
w : AbsoluteValue R S
a b : R
i : ι
ha : 1 < (v i) a
haj : ∀ (j : ι), j ≠ i → (v j) a < 1
haw : w a = 1
hb : 1 < (v i) b
hbw : w b < 1
c : ℕ → R := fun n ↦ a ^ n * b
hcᵢ : Tendsto (fun n ↦ (v i) (c n)) atTop atTop
hcⱼ : ∀ (j : ι), j ≠ i → Tendsto (fun n ↦ (v j) (c n)) atTop (𝓝 0)
⊢ ∃ k, 1 < (v i) k ∧ (∀ (j : ι), j ≠ i → (v j) k < 1) ∧ w k < 1

Tactic:
TopologicalSpace.tendsto_nhds_generateFrom_iff,

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁷ : Field R
inst✝⁶ : Field S
inst✝⁵ : LinearOrder S
inst✝⁴ : TopologicalSpace S
inst✝³ : IsStrictOrderedRing S
inst✝² : Archimedean S
inst✝¹ : OrderTopology S
ι : Type u_3
inst✝ : Finite ι
v : ι → AbsoluteValue R S
w : AbsoluteValue R S
a b : R
i : ι
ha : 1 < (v i) a
haj : ∀ (j : ι), j ≠ i → (v j) a < 1
haw : w a = 1
hb : 1 < (v i) b
hbw : w b < 1
c : ℕ → R := fun n ↦ a ^ n * b
hcᵢ : Tendsto (fun n ↦ (v i) (c n)) atTop atTop
hcⱼ : ∀ (j : ι), j ≠ i → ∀ s ∈ {s | ∃ a, s = Set.Ioi a ∨ s = Set.Iio a}, 0 ∈ s → (fun n ↦ (v j) (c n)) ⁻¹' s ∈ atTop
⊢ ∃ k, 1 < (v i) k ∧ (∀ (j : ι), j ≠ i → (v j) k < 1) ∧ w k < 1
Module: Mathlib.Analysis.AbsoluteValue.Equivalence

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁷ : Field R
inst✝⁶ : Field S
inst✝⁵ : LinearOrder S
inst✝⁴ : TopologicalSpace S
inst✝³ : IsStrictOrderedRing S
inst✝² : Archimedean S
inst✝¹ : OrderTopology S
ι : Type u_3
inst✝ : Finite ι
v : ι → AbsoluteValue R S
w : AbsoluteValue R S
a b : R
i : ι
ha : 1 < (v i) a
haj : ∀ (j : ι), j ≠ i → (v j) a < 1
haw : 1 < w a
hb : 1 < (v i) b
hbw : w b < 1
c : ℕ → R := fun n ↦ 1 / (1 + a⁻¹ ^ n) * b
hcᵢ : Tendsto (fun n ↦ (v i) (c n)) atTop (𝓝 ((v i) b))
hcₙ : Tendsto (fun n ↦ w (c n)) atTop (𝓝 (w b))
hcⱼ : ∀ (j : ι), j ≠ i → Tendsto (fun n ↦ (v j) (c n)) atTop (𝓝 0)
⊢ ∃ k, 1 < (v i) k ∧ (∀ (j : ι), j ≠ i → (v j) k < 1) ∧ w k < 1

Tactic:
TopologicalSpace.tendsto_nhds_generateFrom_iff,

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁷ : Field R
inst✝⁶ : Field S
inst✝⁵ : LinearOrder S
inst✝⁴ : TopologicalSpace S
inst✝³ : IsStrictOrderedRing S
inst✝² : Archimedean S
inst✝¹ : OrderTopology S
ι : Type u_3
inst✝ : Finite ι
v : ι → AbsoluteValue R S
w : AbsoluteValue R S
a b : R
i : ι
ha : 1 < (v i) a
haj : ∀ (j : ι), j ≠ i → (v j) a < 1
haw : 1 < w a
hb : 1 < (v i) b
hbw : w b < 1
c : ℕ → R := fun n ↦ 1 / (1 + a⁻¹ ^ n) * b
hcᵢ : Tendsto (fun n ↦ (v i) (c n)) atTop (𝓝 ((v i) b))
hcₙ : Tendsto (fun n ↦ w (c n)) atTop (𝓝 (w b))
hcⱼ : ∀ (j : ι), j ≠ i → ∀ s ∈ {s | ∃ a, s = Set.Ioi a ∨ s = Set.Iio a}, 0 ∈ s → (fun n ↦ (v j) (c n)) ⁻¹' s ∈ atTop
⊢ ∃ k, 1 < (v i) k ∧ (∀ (j : ι), j ≠ i → (v j) k < 1) ∧ w k < 1
Module: Mathlib.Analysis.Normed.Module.Connected

Goal state before:
pp: case h₁
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
h : 1 < Module.rank ℝ E
x : E
r : ℝ
hr : 0 ≤ r
rpos : 0 < r
f : E → E := ⋯
A : ContinuousOn f {0}ᶜ
B : IsPathConnected {0}ᶜ
C : IsPathConnected (f '' {0}ᶜ)
⊢ f '' {0}ᶜ ⊆ sphere x r

Tactic:
rintro - ⟨y, hy, rfl⟩
      have : ‖y‖ ≠ 0 := by simpa using hy
      simp [f, norm_smul, abs_of_nonneg hr, mul_assoc, inv_mul_cancel₀ this]

Goal state after:
Module: Mathlib.Analysis.AbsoluteValue.Equivalence

Goal state before:
pp: F : Type u_1
inst✝ : Field F
v w : AbsoluteValue F ℝ
h : v.IsEquiv w
a : F
ha₀ : a ≠ 0
ha₁ : v a ≠ 1
b : F
hb₀ : b ≠ 0
hb₁ : v b ≠ 1
h_ne : log (v b) / log (w b) ≠ log (v a) / log (w a)
ha : 1 < v a
hb : 1 < v b
h_lt : log (v b) * log (w a) < log (v a) * log (w b)
hwa : 1 < w a
hwb : 1 < w b
⊢ False

Tactic:
mul_comm (v a).log,

Goal state after:
F : Type u_1
inst✝ : Field F
v w : AbsoluteValue F ℝ
h : v.IsEquiv w
a : F
ha₀ : a ≠ 0
ha₁ : v a ≠ 1
b : F
hb₀ : b ≠ 0
hb₁ : v b ≠ 1
h_ne : log (v b) / log (w b) ≠ log (v a) / log (w a)
ha : 1 < v a
hb : 1 < v b
h_lt : log (v b) * log (w a) < log (w b) * log (v a)
hwa : 1 < w a
hwb : 1 < w b
⊢ False
Module: Mathlib.Analysis.SpecialFunctions.Complex.Analytic

Goal state before:
pp: ⊢ HasFPowerSeriesAt (fun x ↦ Real.log (1 + x)) (FormalMultilinearSeries.ofScalars ℝ fun n ↦ -(-1) ^ n / ↑n) 0

Tactic:
by
  convert HasFPowerSeriesAt.comp_sub hasFPowerSeriesAt_log_one (-1) using 3 <;> ring

Goal state after:
Module: Mathlib.Analysis.Analytic.Order

Goal state before:
pp: case succ
𝕜 : Type u_1
E : Type u_2
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : CharZero 𝕜
inst✝ : CompleteSpace E
z₀ : 𝕜
n : ℕ
f : 𝕜 → E
IH : analyticOrderAt (deriv f) z₀ = ↑n ↔ (∀ k < n, iteratedDeriv k (deriv f) z₀ = 0) ∧ iteratedDeriv n (deriv f) z₀ ≠ 0
hf : AnalyticAt 𝕜 f z₀
⊢ analyticOrderAt f z₀ = ↑(n + 1) ↔ (∀ k < n + 1, iteratedDeriv k f z₀ = 0) ∧ iteratedDeriv (n + 1) f z₀ ≠ 0

Tactic:
simp_rw [← iteratedDeriv_succ'] at IH

Goal state after:
case succ
𝕜 : Type u_1
E : Type u_2
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : CharZero 𝕜
inst✝ : CompleteSpace E
z₀ : 𝕜
n : ℕ
f : 𝕜 → E
hf : AnalyticAt 𝕜 f z₀
IH : analyticOrderAt (deriv f) z₀ = ↑n ↔ (∀ k < n, iteratedDeriv (k + 1) f z₀ = 0) ∧ iteratedDeriv (n + 1) f z₀ ≠ 0
⊢ analyticOrderAt f z₀ = ↑(n + 1) ↔ (∀ k < n + 1, iteratedDeriv k f z₀ = 0) ∧ iteratedDeriv (n + 1) f z₀ ≠ 0
Module: Mathlib.Analysis.Meromorphic.Basic

Goal state before:
pp: 𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_3
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
x : 𝕜
f g : 𝕜 → E
hf : MeromorphicAt f x
hg : MeromorphicAt g x
z : 𝕜
⊢ (f - g) z = (f + -g) z

Tactic:
simp_rw [Pi.sub_apply, Pi.add_apply, Pi.neg_apply, sub_eq_add_neg]

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

Goal state before:
pp: 𝕜 : Type u_1
inst✝³ : NontriviallyNormedField 𝕜
E : Type u_3
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : CompleteSpace E
f : 𝕜 → E
x : 𝕜
n : ℤ
g : 𝕜 → E
h₁g : AnalyticAt 𝕜 g x
h₂g : ∀ᶠ (z : 𝕜) in 𝓝[≠] x, f z = (z - x) ^ n • g z
z₀ : 𝕜
⊢ AnalyticAt 𝕜 g z₀ →
    z₀ ∈ {x}ᶜ → deriv (fun z ↦ (z - x) ^ n • g z) z₀ = (↑n * (z₀ - x) ^ (n - 1)) • g z₀ + (z₀ - x) ^ n • deriv g z₀

Tactic:
h₁

Goal state after:
𝕜 : Type u_1
inst✝³ : NontriviallyNormedField 𝕜
E : Type u_3
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : CompleteSpace E
f : 𝕜 → E
x : 𝕜
n : ℤ
g : 𝕜 → E
h₁g : AnalyticAt 𝕜 g x
h₂g : ∀ᶠ (z : 𝕜) in 𝓝[≠] x, f z = (z - x) ^ n • g z
z₀ : 𝕜
h₁ : AnalyticAt 𝕜 g z₀
⊢ z₀ ∈ {x}ᶜ → deriv (fun z ↦ (z - x) ^ n • g z) z₀ = (↑n * (z₀ - x) ^ (n - 1)) • g z₀ + (z₀ - x) ^ n • deriv g z₀
Module: Mathlib.Analysis.SpecialFunctions.Pow.Deriv

Goal state before:
pp: p : ℂ × ℂ
hp : p.1 ∈ slitPlane
A : p.1 ≠ 0
⊢ HasStrictFDerivAt (fun x ↦ x.1 ^ x.2)
    ((p.2 * p.1 ^ (p.2 - 1)) • ContinuousLinearMap.fst ℂ ℂ ℂ + (p.1 ^ p.2 * log p.1) • ContinuousLinearMap.snd ℂ ℂ ℂ) p

Tactic:
have : (fun x : ℂ × ℂ => x.1 ^ x.2) =ᶠ[𝓝 p] fun x => exp (log x.1 * x.2) :=
    ((isOpen_ne.preimage continuous_fst).eventually_mem A).mono fun p hp =>
      cpow_def_of_ne_zero hp _

Goal state after:
p : ℂ × ℂ
hp : p.1 ∈ slitPlane
A : p.1 ≠ 0
this : (fun x ↦ x.1 ^ x.2) =ᶠ[𝓝 p] fun x ↦ cexp (log x.1 * x.2)
⊢ HasStrictFDerivAt (fun x ↦ x.1 ^ x.2)
    ((p.2 * p.1 ^ (p.2 - 1)) • ContinuousLinearMap.fst ℂ ℂ ℂ + (p.1 ^ p.2 * log p.1) • ContinuousLinearMap.snd ℂ ℂ ℂ) p
Module: Mathlib.RingTheory.Binomial

Goal state before:
pp: case ofNat
k n : ℕ
⊢ (↑k.factorial *
      match ofNat n with
      | ofNat n => ↑((n + k - 1).choose k)
      | -[n+1] => ↑(↑k).negOnePow * ↑((n + 1).choose k)) =
    (ascPochhammer ℕ k).smeval (ofNat n)

Tactic:
simp only [Int.ofNat_eq_natCast, Int.ofNat_mul_ofNat]
      rw [← Nat.descFactorial_eq_factorial_mul_choose, smeval_at_natCast, ← eval_eq_smeval n,
        ascPochhammer_nat_eq_descFactorial]

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Pow.Deriv

Goal state before:
pp: case pos
x p : ℝ
h : p = 0
⊢ deriv (fun x ↦ x ^ p) x = p * x ^ (p - 1)

pp: case neg
x p : ℝ
h : p ≠ 0
⊢ deriv (fun x ↦ x ^ p) x = p * x ^ (p - 1)

Tactic:
· simp [h]

Goal state after:
case neg
x p : ℝ
h : p ≠ 0
⊢ deriv (fun x ↦ x ^ p) x = p * x ^ (p - 1)
Module: Mathlib.Analysis.SpecialFunctions.Log.ERealExp

Goal state before:
pp: case bot
y : EReal
h : ⊥ < y
⊢ ⊥.exp < y.exp

Tactic:
rw [exp_bot, pos_iff_ne_zero, ne_eq, exp_eq_zero_iff]

Goal state after:
case bot
y : EReal
h : ⊥ < y
⊢ ¬y = ⊥
Module: Mathlib.Analysis.SpecialFunctions.Log.ERealExp

Goal state before:
pp: case top
y : EReal
h : ⊤ < y
⊢ ⊤.exp < y.exp

Tactic:
exact (not_top_lt h).elim

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Log.ENNRealLogExp

Goal state before:
pp: case pos
x : ℝ≥0∞
hx_top : ¬x = ∞
hx_zero : x = 0
⊢ x.log.exp = x

pp: case neg
x : ℝ≥0∞
hx_top : ¬x = ∞
hx_zero : ¬x = 0
⊢ x.log.exp = x

Tactic:
· simp [hx_zero]

Goal state after:
case neg
x : ℝ≥0∞
hx_top : ¬x = ∞
hx_zero : ¬x = 0
⊢ x.log.exp = x
Module: Mathlib.Analysis.SpecialFunctions.Log.ENNRealLog

Goal state before:
pp: case inr.inr.inr.inr
x y : ℝ≥0∞
x_real : 0 < x.toReal
y_real : 0 < y.toReal
⊢ (x * y).log = ↑(Real.log x.toReal) + y.log

Tactic:
rw_mod_cast [log_pos_real', log_pos_real' y_real, ENNReal.toReal_mul]
      · exact Real.log_mul x_real.ne' y_real.ne'
      rw [toReal_mul]
      positivity

Goal state after:
Module: Mathlib.Analysis.Asymptotics.LinearGrowth

Goal state before:
pp: u : ℕ → EReal
a : EReal
⊢ linearGrowthInf u ≤ a ↔ ∀ b > a, ∃ᶠ (n : ℕ) in atTop, u n ≤ b * ↑n

Tactic:
by
  rw [linearGrowthInf, liminf_le_iff']
  refine forall₂_congr fun b _ ↦ frequently_congr (eventually_atTop.2 ⟨1, fun n _ ↦ ?_⟩)
  rw [div_le_iff_le_mul (by norm_cast) (natCast_ne_top n), mul_comm _ b]

Goal state after:
Module: Mathlib.Analysis.Asymptotics.LinearGrowth

Goal state before:
pp: ι : Type u_1
inst✝ : Finite ι
u : ι → ℕ → EReal
⊢ linearGrowthSup (⨆ i, u i) = ⨆ i, linearGrowthSup (u i)

Tactic:
by
  rw [← iSup_univ, linearGrowthSup_biSup u Set.finite_univ, iSup_univ]

Goal state after:
Module: Mathlib.Analysis.Asymptotics.LinearGrowth

Goal state before:
pp: u : ℕ → EReal
h : Monotone u
m : ℕ
hm : ¬u m = ⊥ m
m_n : ∀ᶠ (n : ℕ) in atTop, u m ≤ u n
⊢ 0 ≤ linearGrowthInf u

Tactic:
rcases eq_or_ne (u m) ⊤ with hm' | hm'

Goal state after:
case inl
u : ℕ → EReal
h : Monotone u
m : ℕ
hm : ¬u m = ⊥ m
m_n : ∀ᶠ (n : ℕ) in atTop, u m ≤ u n
hm' : u m = ⊤
⊢ 0 ≤ linearGrowthInf u

case inr
u : ℕ → EReal
h : Monotone u
m : ℕ
hm : ¬u m = ⊥ m
m_n : ∀ᶠ (n : ℕ) in atTop, u m ≤ u n
hm' : u m ≠ ⊤
⊢ 0 ≤ linearGrowthInf u
Module: Mathlib.Analysis.Asymptotics.ExpGrowth

Goal state before:
pp: case inr
u v : ℕ → ℝ≥0∞
b : ℝ≥0∞
hb : b ≠ ∞
h : ∀ᶠ (n : ℕ) in atTop, u n ≤ b * v n
b_pos : 0 < b
⊢ (expGrowthInf fun x ↦ b * v x) ≤ expGrowthInf v

Tactic:
· apply (expGrowthInf_mul_le _ _).trans_eq <;> rw [expGrowthSup_const b_pos.ne' hb]
    · exact zero_add (expGrowthInf v)
    · exact .inl zero_ne_bot
    · exact .inl zero_ne_top

Goal state after:
Module: Mathlib.MeasureTheory.Function.AEMeasurableOrder

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
β : Type u_2
inst✝⁶ : CompleteLinearOrder β
inst✝⁵ : DenselyOrdered β
inst✝⁴ : TopologicalSpace β
inst✝³ : OrderTopology β
inst✝² : SecondCountableTopology β
inst✝¹ : MeasurableSpace β
inst✝ : BorelSpace β
s : Set β
s_count : s.Countable
s_dense : Dense s
f : α → β
h :
  ∀ p ∈ s,
    ∀ q ∈ s, p < q → ∃ u v, MeasurableSet u ∧ MeasurableSet v ∧ {x | f x < p} ⊆ u ∧ {x | q < f x} ⊆ v ∧ μ (u ∩ v) = 0
this : Encodable ↑s
⊢ AEMeasurable f μ

Tactic:
have h' : ∀ p q, ∃ u v, MeasurableSet u ∧ MeasurableSet v ∧
      { x | f x < p } ⊆ u ∧ { x | q < f x } ⊆ v ∧ (p ∈ s → q ∈ s → p < q → μ (u ∩ v) = 0) := by
    intro p q
    by_cases H : p ∈ s ∧ q ∈ s ∧ p < q
    · rcases h p H.1 q H.2.1 H.2.2 with ⟨u, v, hu, hv, h'u, h'v, hμ⟩
      exact ⟨u, v, hu, hv, h'u, h'v, fun _ _ _ => hμ⟩
    · refine
        ⟨univ, univ, MeasurableSet.univ, MeasurableSet.univ, subset_univ _, subset_univ _,
          fun ps qs pq => ?_⟩
      exact (H ⟨ps, qs, pq⟩).elim

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
β : Type u_2
inst✝⁶ : CompleteLinearOrder β
inst✝⁵ : DenselyOrdered β
inst✝⁴ : TopologicalSpace β
inst✝³ : OrderTopology β
inst✝² : SecondCountableTopology β
inst✝¹ : MeasurableSpace β
inst✝ : BorelSpace β
s : Set β
s_count : s.Countable
s_dense : Dense s
f : α → β
h :
  ∀ p ∈ s,
    ∀ q ∈ s, p < q → ∃ u v, MeasurableSet u ∧ MeasurableSet v ∧ {x | f x < p} ⊆ u ∧ {x | q < f x} ⊆ v ∧ μ (u ∩ v) = 0
this : Encodable ↑s
h' :
  ∀ (p q : β),
    ∃ u v,
      MeasurableSet u ∧
        MeasurableSet v ∧ {x | f x < p} ⊆ u ∧ {x | q < f x} ⊆ v ∧ (p ∈ s → q ∈ s → p < q → μ (u ∩ v) = 0)
⊢ AEMeasurable f μ
Module: Mathlib.MeasureTheory.Function.AEEqOfLIntegral

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hfi : ∫⁻ (x : α), f x ∂μ ≠ ∞
hgi : ∫⁻ (x : α), g x ∂μ ≠ ∞
hfg : ∀ ⦃s : Set α⦄, MeasurableSet s → μ s < ∞ → ∫⁻ (x : α) in s, f x ∂μ = ∫⁻ (x : α) in s, g x ∂μ
hf' : AEFinStronglyMeasurable f μ
hg' : AEFinStronglyMeasurable g μ
s : Set α := hf'.sigmaFiniteSet
⊢ f =ᵐ[μ] g

Tactic:
let t := hg'.sigmaFiniteSet

Goal state after:
α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hfi : ∫⁻ (x : α), f x ∂μ ≠ ∞
hgi : ∫⁻ (x : α), g x ∂μ ≠ ∞
hfg : ∀ ⦃s : Set α⦄, MeasurableSet s → μ s < ∞ → ∫⁻ (x : α) in s, f x ∂μ = ∫⁻ (x : α) in s, g x ∂μ
hf' : AEFinStronglyMeasurable f μ
hg' : AEFinStronglyMeasurable g μ
s : Set α := hf'.sigmaFiniteSet
t : Set α := hg'.sigmaFiniteSet
⊢ f =ᵐ[μ] g
Module: Mathlib.MeasureTheory.Measure.Sub

Goal state before:
pp: case a
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
h₁ : MeasurableSet s
h₂ : ν ≤ μ
measure_sub : Measure α := ofMeasurable (fun t x ↦ μ t - ν t) ⋯ ⋯
h_measure_sub_add : ν + measure_sub = μ
d : Measure α
h_d : ν + measure_sub ≤ d + ν
⊢ measure_sub ≤ d

Tactic:
add_comm d

Goal state after:
case a
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
h₁ : MeasurableSet s
h₂ : ν ≤ μ
measure_sub : Measure α := ofMeasurable (fun t x ↦ μ t - ν t) ⋯ ⋯
h_measure_sub_add : ν + measure_sub = μ
d : Measure α
h_d : ν + measure_sub ≤ ν + d
⊢ measure_sub ≤ d
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: case left.left
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝ : ν.HaveLebesgueDecomposition μ
hμν : μ ≪ ν.singularPart μ + μ.withDensity (ν.rnDeriv μ)
s : Set α
x✝ : MeasurableSet s
hνs : (μ.withDensity (ν.rnDeriv μ)) s = 0
t : Set α
left✝ : MeasurableSet t
ht1 : (ν.singularPart μ) t = 0
ht2 : μ tᶜ = 0
⊢ (ν.singularPart μ) (s ∩ t) = 0

pp: case left.right
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝ : ν.HaveLebesgueDecomposition μ
hμν : μ ≪ ν.singularPart μ + μ.withDensity (ν.rnDeriv μ)
s : Set α
x✝ : MeasurableSet s
hνs : (μ.withDensity (ν.rnDeriv μ)) s = 0
t : Set α
left✝ : MeasurableSet t
ht1 : (ν.singularPart μ) t = 0
ht2 : μ tᶜ = 0
⊢ (μ.withDensity (ν.rnDeriv μ)) (s ∩ t) = 0

Tactic:
· exact measure_mono_null Set.inter_subset_right ht1

Goal state after:
case left.right
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝ : ν.HaveLebesgueDecomposition μ
hμν : μ ≪ ν.singularPart μ + μ.withDensity (ν.rnDeriv μ)
s : Set α
x✝ : MeasurableSet s
hνs : (μ.withDensity (ν.rnDeriv μ)) s = 0
t : Set α
left✝ : MeasurableSet t
ht1 : (ν.singularPart μ) t = 0
ht2 : μ tᶜ = 0
⊢ (μ.withDensity (ν.rnDeriv μ)) (s ∩ t) = 0
Module: Mathlib.MeasureTheory.Covering.Differentiation

Goal state before:
pp: α : Type u_1
inst✝¹ : PseudoMetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
inst✝ : SecondCountableTopology α
⊢ ∀ᵐ (x : α) ∂μ, ∀ᶠ (a : Set α) in v.filterAt x, 0 < μ a

Tactic:
set s := {x | ¬∀ᶠ a in v.filterAt x, 0 < μ a} with hs
  simp -zeta only [not_lt, not_eventually, nonpos_iff_eq_zero] at hs
  change μ s = 0
  let f : α → Set (Set α) := fun _ => {a | μ a = 0}
  have h : v.FineSubfamilyOn f s := by
    intro x hx ε εpos
    rw [hs] at hx
    simp only [frequently_filterAt_iff, gt_iff_lt, mem_ofPred_eq] at hx
    rcases hx ε εpos with ⟨a, a_sets, ax, μa⟩
    exact ⟨a, ⟨a_sets, μa⟩, ax⟩
  refine le_antisymm ?_ bot_le
  calc
    μ s ≤ ∑' x : h.index, μ (h.covering x) := h.measure_le_tsum
    _ = ∑' x : h.index, 0 := by congr; ext1 x; exact h.covering_mem x.2
    _ = 0 := by simp only [tsum_zero]

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

Goal state before:
pp: case refine_2
α : Type u_1
inst✝⁵ : PseudoMetricSpace α
inst✝⁴ : MeasurableSpace α
μ : Measure α
inst✝³ : IsUnifLocDoublingMeasure μ
inst✝² : SecondCountableTopology α
inst✝¹ : BorelSpace α
inst✝ : IsLocallyFiniteMeasure μ
K : ℝ
x : α
ι : Type u_2
l : Filter ι
w : ι → α
δ : ι → ℝ
δlim : Tendsto δ l (𝓝[>] 0)
xmem : ∀ᶠ (j : ι) in l, x ∈ closedBall (w j) (K * δ j)
ε : ℝ
hε : ε > 0
⊢ ∀ᶠ (i : ι) in l, closedBall (w i) (δ i) ⊆ closedBall x ε

Tactic:
rcases l.eq_or_neBot with rfl | h
    · simp
    have hK : 0 ≤ K := by
      rcases (xmem.and (δlim self_mem_nhdsWithin)).exists with ⟨j, hj, h'j⟩
      have : 0 ≤ K * δ j := nonempty_closedBall.1 ⟨x, hj⟩
      exact (mul_nonneg_iff_left_nonneg_of_pos (mem_Ioi.1 h'j)).1 this
    have δpos := eventually_mem_of_tendsto_nhdsWithin δlim
    replace δlim := tendsto_nhds_of_tendsto_nhdsWithin δlim
    replace hK : 0 < K + 1 := by linarith
    apply (((Metric.tendsto_nhds.mp δlim _ (div_pos hε hK)).and δpos).and xmem).mono
    rintro j ⟨⟨hjε, hj₀ : 0 < δ j⟩, hx⟩ y hy
    replace hjε : (K + 1) * δ j < ε := by
      simpa [abs_eq_self.mpr hj₀.le] using (lt_div_iff₀' hK).mp hjε
    simp only [mem_closedBall] at hx hy ⊢
    linarith [dist_triangle_right y x (w j)]

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

Goal state before:
pp: case pos
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
h : ¬μ ⟂ₘ ν
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → ((1 / (↑n + 1)) • ν) (t ∩ f n) ≤ μ (t ∩ f n)
hf₃ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ (f n)ᶜ) ≤ ((1 / (↑n + 1)) • ν) (t ∩ (f n)ᶜ)
A : Set α := ⋂ n, (f n)ᶜ
hAmeas : MeasurableSet A
hA₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ A) ≤ ((1 / (↑n + 1)) • ν) (t ∩ A)
μA νA : ℝ≥0
hA₃ : ∀ (n : ℕ), ↑μA ≤ ↑(1 / (↑n + 1)) * ↑νA
hb : 0 < νA
c : ℝ≥0
hc : 0 < c
n : ℕ
hn : 1 / (↑n + 1) < ↑c * (↑νA)⁻¹
hb₁ : 0 < (↑νA)⁻¹
h' : 1 / (↑n + 1) * νA < c
⊢ μA ≤ 1 / (↑n + 1) * νA

Tactic:
rw [← ENNReal.coe_le_coe, ENNReal.coe_mul]

Goal state after:
case pos
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
h : ¬μ ⟂ₘ ν
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → ((1 / (↑n + 1)) • ν) (t ∩ f n) ≤ μ (t ∩ f n)
hf₃ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ (f n)ᶜ) ≤ ((1 / (↑n + 1)) • ν) (t ∩ (f n)ᶜ)
A : Set α := ⋂ n, (f n)ᶜ
hAmeas : MeasurableSet A
hA₂ : ∀ (n : ℕ) (t : Set α), MeasurableSet t → μ (t ∩ A) ≤ ((1 / (↑n + 1)) • ν) (t ∩ A)
μA νA : ℝ≥0
hA₃ : ∀ (n : ℕ), ↑μA ≤ ↑(1 / (↑n + 1)) * ↑νA
hb : 0 < νA
c : ℝ≥0
hc : 0 < c
n : ℕ
hn : 1 / (↑n + 1) < ↑c * (↑νA)⁻¹
hb₁ : 0 < (↑νA)⁻¹
h' : 1 / (↑n + 1) * νA < c
⊢ ↑μA ≤ ↑(1 / (↑n + 1)) * ↑νA
Module: Mathlib.MeasureTheory.Measure.Decomposition.Lebesgue

Goal state before:
pp: case refine_2
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
g : ℕ → ℝ≥0∞
h✝ : Monotone g
hg₂ : Filter.Tendsto g Filter.atTop (nhds (sSup (measurableLEEval ν μ)))
f : ℕ → α → ℝ≥0∞
hf₁ : ∀ (n : ℕ), f n ∈ measurableLE ν μ
hf₂ : ∀ (n : ℕ), (fun f ↦ ∫⁻ (x : α), f x ∂ν) (f n) = g n
ξ : α → ℝ≥0∞ := ⨆ n, ⨆ k, ⨆ (_ : k ≤ n), f k
hξ : ξ = ⨆ n, ⨆ k, ⨆ (_ : k ≤ n), f k
⊢ ∀ᵐ (x : α) ∂ν, Monotone fun n ↦ (⨆ k, ⨆ (_ : k ≤ n), f k) x

Tactic:
refine Filter.Eventually.of_forall fun a ↦ ?_

Goal state after:
case refine_2
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
g : ℕ → ℝ≥0∞
h✝ : Monotone g
hg₂ : Filter.Tendsto g Filter.atTop (nhds (sSup (measurableLEEval ν μ)))
f : ℕ → α → ℝ≥0∞
hf₁ : ∀ (n : ℕ), f n ∈ measurableLE ν μ
hf₂ : ∀ (n : ℕ), (fun f ↦ ∫⁻ (x : α), f x ∂ν) (f n) = g n
ξ : α → ℝ≥0∞ := ⨆ n, ⨆ k, ⨆ (_ : k ≤ n), f k
hξ : ξ = ⨆ n, ⨆ k, ⨆ (_ : k ≤ n), f k
a : α
⊢ Monotone fun n ↦ (⨆ k, ⨆ (_ : k ≤ n), f k) a