mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Normed.Group.Continuity

Goal state before:
pp: E : Type u_4
inst✝ : SeminormedCommGroup E
a : E
s : Subgroup E
hg : a ∈ closure[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑s
b : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < b n
u : ℕ → E
u_in : ∀ (n : ℕ), u n ∈ s
lim_u : Tendsto u atTop (𝓝 a)
n₀ : ℕ
hn₀ : ∀ n ≥ n₀, ‖(u n)⁻¹ * a‖ < b 0
z : ℕ → E := fun n ↦ u (n + n₀)
lim_z : Tendsto z atTop (𝓝 a)
mem_𝓤 : ∀ (n : ℕ), {p | ‖p.1⁻¹ * p.2‖ < b (n + 1)} ∈ 𝓤 E
φ : ℕ → ℕ
φ_extr : StrictMono φ
hφ : ∀ (n : ℕ), ‖(z (φ (n + 1)))⁻¹ * z (φ n)‖ < b (n + 1)
w : ℕ → E := z ∘ φ
hw : Tendsto w atTop (𝓝 a)
v : ℕ → E := fun i ↦ if i = 0 then w 0 else (w (i - 1))⁻¹ * w i
⊢ ∃ v,
    Tendsto (fun n ↦ ∏ i ∈ range (n + 1), v i) atTop (𝓝 a) ∧
      (∀ (n : ℕ), v n ∈ s) ∧ ‖(v 0)⁻¹ * a‖ < b 0 ∧ ∀ (n : ℕ), 0 < n → ‖v n‖ < b n

Tactic:
refine ⟨v, ?_, ?_, hn₀ _ (n₀.le_add_left _), ?_⟩

Goal state after:
case refine_1
E : Type u_4
inst✝ : SeminormedCommGroup E
a : E
s : Subgroup E
hg : a ∈ closure[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑s
b : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < b n
u : ℕ → E
u_in : ∀ (n : ℕ), u n ∈ s
lim_u : Tendsto u atTop (𝓝 a)
n₀ : ℕ
hn₀ : ∀ n ≥ n₀, ‖(u n)⁻¹ * a‖ < b 0
z : ℕ → E := fun n ↦ u (n + n₀)
lim_z : Tendsto z atTop (𝓝 a)
mem_𝓤 : ∀ (n : ℕ), {p | ‖p.1⁻¹ * p.2‖ < b (n + 1)} ∈ 𝓤 E
φ : ℕ → ℕ
φ_extr : StrictMono φ
hφ : ∀ (n : ℕ), ‖(z (φ (n + 1)))⁻¹ * z (φ n)‖ < b (n + 1)
w : ℕ → E := z ∘ φ
hw : Tendsto w atTop (𝓝 a)
v : ℕ → E := fun i ↦ if i = 0 then w 0 else (w (i - 1))⁻¹ * w i
⊢ Tendsto (fun n ↦ ∏ i ∈ range (n + 1), v i) atTop (𝓝 a)

case refine_2
E : Type u_4
inst✝ : SeminormedCommGroup E
a : E
s : Subgroup E
hg : a ∈ closure[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑s
b : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < b n
u : ℕ → E
u_in : ∀ (n : ℕ), u n ∈ s
lim_u : Tendsto u atTop (𝓝 a)
n₀ : ℕ
hn₀ : ∀ n ≥ n₀, ‖(u n)⁻¹ * a‖ < b 0
z : ℕ → E := fun n ↦ u (n + n₀)
lim_z : Tendsto z atTop (𝓝 a)
mem_𝓤 : ∀ (n : ℕ), {p | ‖p.1⁻¹ * p.2‖ < b (n + 1)} ∈ 𝓤 E
φ : ℕ → ℕ
φ_extr : StrictMono φ
hφ : ∀ (n : ℕ), ‖(z (φ (n + 1)))⁻¹ * z (φ n)‖ < b (n + 1)
w : ℕ → E := z ∘ φ
hw : Tendsto w atTop (𝓝 a)
v : ℕ → E := fun i ↦ if i = 0 then w 0 else (w (i - 1))⁻¹ * w i
⊢ ∀ (n : ℕ), v n ∈ s

case refine_3
E : Type u_4
inst✝ : SeminormedCommGroup E
a : E
s : Subgroup E
hg : a ∈ closure[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑s
b : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < b n
u : ℕ → E
u_in : ∀ (n : ℕ), u n ∈ s
lim_u : Tendsto u atTop (𝓝 a)
n₀ : ℕ
hn₀ : ∀ n ≥ n₀, ‖(u n)⁻¹ * a‖ < b 0
z : ℕ → E := fun n ↦ u (n + n₀)
lim_z : Tendsto z atTop (𝓝 a)
mem_𝓤 : ∀ (n : ℕ), {p | ‖p.1⁻¹ * p.2‖ < b (n + 1)} ∈ 𝓤 E
φ : ℕ → ℕ
φ_extr : StrictMono φ
hφ : ∀ (n : ℕ), ‖(z (φ (n + 1)))⁻¹ * z (φ n)‖ < b (n + 1)
w : ℕ → E := z ∘ φ
hw : Tendsto w atTop (𝓝 a)
v : ℕ → E := fun i ↦ if i = 0 then w 0 else (w (i - 1))⁻¹ * w i
⊢ ∀ (n : ℕ), 0 < n → ‖v n‖ < b n
Module: Mathlib.Topology.UniformSpace.Completion

Goal state before:
pp: case neg
α : Type u
inst✝² : UniformSpace α
β : Type v
inst✝¹ : UniformSpace β
inst✝ : CompleteSpace β
f : α → β
hf : ¬UniformContinuous f
⊢ UniformContinuous fun x ↦ f ⋯.some

Tactic:
exact uniformContinuous_of_const fun a _b => by congr

Goal state after:
Module: Mathlib.Topology.Instances.ENNReal.Lemmas

Goal state before:
pp: case inl.refine_2
ι : Type u_4
l : Filter ι
x : ι → ℝ
hf : liminf (fun i ↦ ↑(Real.nnabs (x i))) l ≠ ∞
hbdd : ¬IsBoundedUnder (fun x1 x2 ↦ x1 ≤ x2) l x
R : ℝ
hR : ∃ᶠ (n : ι) in l, x n < R
q : ℚ
hq : R < ↑q
⊢ ∃ᶠ (i : ι) in l, ↑(q + 1) < x i

Tactic:
· simp only [IsBoundedUnder, IsBounded, eventually_map, not_exists] at hbdd
      refine fun hcon => hbdd ↑(q + 1) ?_
      filter_upwards [hcon] with x hx using not_lt.1 hx

Goal state after:
Module: Mathlib.Topology.Algebra.UniformMulAction

Goal state before:
pp: case hg
R : Type u
M : Type v
N : Type w
X : Type x
Y : Type y
inst✝⁶ : UniformSpace X
inst✝⁵ : UniformSpace Y
inst✝⁴ : SMul M X
inst✝³ : SMul N X
inst✝² : SMulCommClass M N X
inst✝¹ : UniformContinuousConstSMul M X
inst✝ : UniformContinuousConstSMul N X
m : M
n : N
x : Completion X
hmn : m • n • x = (Completion.map (SMul.smul m) ∘ Completion.map (SMul.smul n)) x
hnm : n • m • x = (Completion.map (SMul.smul n) ∘ Completion.map (SMul.smul m)) x
⊢ UniformContinuous (SMul.smul n)

pp: case hf
R : Type u
M : Type v
N : Type w
X : Type x
Y : Type y
inst✝⁶ : UniformSpace X
inst✝⁵ : UniformSpace Y
inst✝⁴ : SMul M X
inst✝³ : SMul N X
inst✝² : SMulCommClass M N X
inst✝¹ : UniformContinuousConstSMul M X
inst✝ : UniformContinuousConstSMul N X
m : M
n : N
x : Completion X
hmn : m • n • x = (Completion.map (SMul.smul m) ∘ Completion.map (SMul.smul n)) x
hnm : n • m • x = (Completion.map (SMul.smul n) ∘ Completion.map (SMul.smul m)) x
⊢ UniformContinuous (SMul.smul m)

pp: case hg
R : Type u
M : Type v
N : Type w
X : Type x
Y : Type y
inst✝⁶ : UniformSpace X
inst✝⁵ : UniformSpace Y
inst✝⁴ : SMul M X
inst✝³ : SMul N X
inst✝² : SMulCommClass M N X
inst✝¹ : UniformContinuousConstSMul M X
inst✝ : UniformContinuousConstSMul N X
m : M
n : N
x : Completion X
hmn : m • n • x = (Completion.map (SMul.smul m) ∘ Completion.map (SMul.smul n)) x
hnm : n • m • x = (Completion.map (SMul.smul n) ∘ Completion.map (SMul.smul m)) x
⊢ UniformContinuous (SMul.smul m)

pp: case hf
R : Type u
M : Type v
N : Type w
X : Type x
Y : Type y
inst✝⁶ : UniformSpace X
inst✝⁵ : UniformSpace Y
inst✝⁴ : SMul M X
inst✝³ : SMul N X
inst✝² : SMulCommClass M N X
inst✝¹ : UniformContinuousConstSMul M X
inst✝ : UniformContinuousConstSMul N X
m : M
n : N
x : Completion X
hmn : m • n • x = (Completion.map (SMul.smul m) ∘ Completion.map (SMul.smul n)) x
hnm : n • m • x = (Completion.map (SMul.smul n) ∘ Completion.map (SMul.smul m)) x
⊢ UniformContinuous (SMul.smul n)

Tactic:
repeat' exact uniformContinuous_const_smul _

Goal state after:
Module: Mathlib.Analysis.Normed.Order.Lattice

Goal state before:
pp: G : Type u_2
inst✝⁴ : AddCommGroup G
inst✝³ : PartialOrder G
inst✝² : IsOrderedAddMonoid G
inst✝¹ : TopologicalSpace G
inst✝ : ContinuousSub G
h : IsClosed {x | 0 ≤ x}
this : {p | p.1 ≤ p.2} = (fun p ↦ p.2 - p.1) ⁻¹' {x | 0 ≤ x}
⊢ IsClosed ((fun p ↦ p.2 - p.1) ⁻¹' {x | 0 ≤ x})

Tactic:
exact IsClosed.preimage (continuous_snd.sub continuous_fst) h

Goal state after:
Module: Mathlib.Topology.MetricSpace.IsometricSMul

Goal state before:
pp: G : Type v
X : Type w
inst✝³ : PseudoMetricSpace X
inst✝² : Group G
inst✝¹ : MulAction G X
inst✝ : IsIsometricSMul G X
c : G
x : X
r : ℝ
⊢ c⁻¹ • ball x r = ball (c⁻¹ • x) r

Tactic:
smul_ball

Goal state after:
G : Type v
X : Type w
inst✝³ : PseudoMetricSpace X
inst✝² : Group G
inst✝¹ : MulAction G X
inst✝ : IsIsometricSMul G X
c : G
x : X
r : ℝ
⊢ ball (c⁻¹ • x) r = ball (c⁻¹ • x) r
Module: Mathlib.Analysis.Normed.Field.Basic

Goal state before:
pp: α : Type u_2
inst✝ : NontriviallyNormedField α
r : ℝ
hr : 0 < r
w : α
hw : r⁻¹ < ‖w‖
⊢ ‖w‖⁻¹ ∈ Set.Ioo 0 r

Tactic:
← Set.mem_inv,

Goal state after:
α : Type u_2
inst✝ : NontriviallyNormedField α
r : ℝ
hr : 0 < r
w : α
hw : r⁻¹ < ‖w‖
⊢ ‖w‖ ∈ (Set.Ioo 0 r)⁻¹
Module: Mathlib.Analysis.Normed.Ring.Basic

Goal state before:
pp: G : Type u_1
α : Type u_2
β : Type u_3
ι : Type u_4
inst✝¹ : NormedRing α
inst✝ : NormMulClass α
a✝ b✝ : α
h : a✝ * b✝ = 0
⊢ a✝ = 0 ∨ b✝ = 0

Tactic:
simpa only [← norm_eq_zero (E := α), norm_mul, mul_eq_zero] using h

Goal state after:
Module: Mathlib.Analysis.Normed.MulAction

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝³ : NormedDivisionRing α
inst✝² : SeminormedAddCommGroup β
inst✝¹ : Module α β
inst✝ : NormSMulClass α β
s : α
hs : s ≠ 0
x : β
ε : ℝ
⊢ (fun x ↦ s • x) '' ball x ε = ball (s • x) (‖s‖ * ε)

Tactic:
ext p

Goal state after:
α : Type u_1
β : Type u_2
inst✝³ : NormedDivisionRing α
inst✝² : SeminormedAddCommGroup β
inst✝¹ : Module α β
inst✝ : NormSMulClass α β
s : α
hs : s ≠ 0
x : β
ε : ℝ
p : β
⊢ p ∈ (fun x ↦ s • x) '' ball x ε ↔ p ∈ ball (s • x) (‖s‖ * ε)
Module: Mathlib.Analysis.Normed.MulAction

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝³ : NormedDivisionRing α
inst✝² : SeminormedAddCommGroup β
inst✝¹ : Module α β
inst✝ : NormSMulClass α β
s : α
hs : s ≠ 0
x : β
ε : ℝ
⊢ (fun x ↦ s • x) '' closedBall x ε = closedBall (s • x) (‖s‖ * ε)

Tactic:
ext p

Goal state after:
α : Type u_1
β : Type u_2
inst✝³ : NormedDivisionRing α
inst✝² : SeminormedAddCommGroup β
inst✝¹ : Module α β
inst✝ : NormSMulClass α β
s : α
hs : s ≠ 0
x : β
ε : ℝ
p : β
⊢ p ∈ (fun x ↦ s • x) '' closedBall x ε ↔ p ∈ closedBall (s • x) (‖s‖ * ε)
Module: Mathlib.Data.Finset.Update

Goal state before:
pp: case pos
ι : Type u_1
π : ι → Type u_2
x : (i : ι) → π i
inst✝ : DecidableEq ι
s t : Finset ι
y : (i : ↥s) → π ↑i
z : (i : ↥t) → π ↑i
hst : Disjoint s t
e : ↥s ⊕ ↥t ≃ ↥(s ∪ t) := Finset.union s t hst
i : ι
his : i ∈ s
hit : i ∈ t
⊢ z ⟨i, hit⟩ = if h : True ∨ True then (piFinsetUnion π hst) (y, z) ⟨i, ⋯⟩ else x i

Tactic:
exfalso

Goal state after:
case pos
ι : Type u_1
π : ι → Type u_2
x : (i : ι) → π i
inst✝ : DecidableEq ι
s t : Finset ι
y : (i : ↥s) → π ↑i
z : (i : ↥t) → π ↑i
hst : Disjoint s t
e : ↥s ⊕ ↥t ≃ ↥(s ∪ t) := Finset.union s t hst
i : ι
his : i ∈ s
hit : i ∈ t
⊢ False
Module: Mathlib.GroupTheory.GroupAction.IterateAct

Goal state before:
pp: α : Type u_1
f : α → α
x✝ : IterateMulAct f
⊢ 1 * x✝ = x✝

Tactic:
by ext; apply Nat.zero_add

Goal state after:
Module: Mathlib.MeasureTheory.MeasurableSpace.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : MeasurableSpace β
f : β → α
hf : ∀ (x y : β), f x = f y
a✝ : Nontrivial β
inhabited_h : Inhabited β
⊢ Measurable f

Tactic:
convert! @measurable_const α β _ _ (f default) using 2

Goal state after:
case e'_5
α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : MeasurableSpace β
f : β → α
hf : ∀ (x y : β), f x = f y
a✝ : Nontrivial β
inhabited_h : Inhabited β
x✝ : β
⊢ f x✝ = f default
Module: Mathlib.MeasureTheory.MeasurableSpace.Defs

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
s t : Set α
p : Prop
hs : p → MeasurableSet s
ht : ¬p → MeasurableSet t
⊢ MeasurableSet (if p then s else t)

Tactic:
by
  split_ifs with h
  exacts [hs h, ht h]

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

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_3
inst✝⁴ : NormedField 𝕜
inst✝³ : Infinite 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : Nontrivial E
inst✝ : NormedSpace 𝕜 E
⊢ NoncompactSpace E

Tactic:
by
  by_cases! H : ∃ c : 𝕜, c ≠ 0 ∧ ‖c‖ ≠ 1
  · let := NontriviallyNormedField.ofNormNeOne H
    exact ⟨fun h ↦ NormedSpace.unbounded_univ 𝕜 E h.isBounded⟩
  · rcases exists_ne (0 : E) with ⟨x, hx⟩
    suffices IsClosedEmbedding (Infinite.natEmbedding 𝕜 · • x) from this.noncompactSpace
    refine isClosedEmbedding_of_pairwise_le_dist (norm_pos_iff.2 hx) fun k n hne ↦ ?_
    simp only [dist_eq_norm, ← sub_smul, norm_smul]
    rw [H, one_mul]
    rwa [sub_ne_zero, (Embedding.injective _).ne_iff]

Goal state after:
Module: Mathlib.MeasureTheory.MeasurableSpace.Constructions

Goal state before:
pp: case h₂
β : Type u_2
inst✝¹ : MeasurableSpace β
inst✝ : Countable β
x : β
s : β → Set β
hs : ∀ y ∉ measurableAtom x, x ∈ s y ∧ MeasurableSet (s y) ∧ y ∉ s y
⊢ ⋂ y ∈ (measurableAtom x)ᶜ, s y ⊆ measurableAtom x

Tactic:
apply compl_subset_compl.1

Goal state after:
case h₂
β : Type u_2
inst✝¹ : MeasurableSpace β
inst✝ : Countable β
x : β
s : β → Set β
hs : ∀ y ∉ measurableAtom x, x ∈ s y ∧ MeasurableSet (s y) ∧ y ∉ s y
⊢ (measurableAtom x)ᶜ ⊆ (⋂ y ∈ (measurableAtom x)ᶜ, s y)ᶜ
Module: Mathlib.MeasureTheory.MeasurableSpace.Constructions

Goal state before:
pp: case neg
β : Type u_2
inst✝ : MeasurableSpace β
x y : β
hx : x ∈ measurableAtom y
hy : y ∉ measurableAtom x
⊢ measurableAtom y ⊆ measurableAtom x

Tactic:
exfalso

Goal state after:
case neg
β : Type u_2
inst✝ : MeasurableSpace β
x y : β
hx : x ∈ measurableAtom y
hy : y ∉ measurableAtom x
⊢ False
Module: Mathlib.MeasureTheory.MeasurableSpace.Constructions

Goal state before:
pp: case neg
δ : Type u_4
X : δ → Type u_6
inst✝¹ : (a : δ) → MeasurableSpace (X a)
a : δ
inst✝ : DecidableEq δ
j : δ
h : ¬j = a
⊢ Measurable fun x ↦ x.1 j

Tactic:
exact measurable_pi_iff.1 measurable_fst _

Goal state after:
Module: Mathlib.Data.Sign.Basic

Goal state before:
pp: α : Type u
inst✝¹ : Nonempty α
inst✝ : DecidableEq α
s : Finset α
f : α → ℤ
n : ℕ
h : ∑ i ∈ s, (f i).natAbs ≤ n
⊢ ∃ β x sgn g,
    (∀ (b : β), g b ∉ s → sgn b = 0) ∧ Fintype.card β = n ∧ ∀ a ∈ s, (∑ i, if g i = a then ↑(sgn i) else 0) = f a

Tactic:
obtain ⟨β, _, sgn, g, hg, hβ, hf⟩ := exists_signed_sum s f

Goal state after:
α : Type u
inst✝¹ : Nonempty α
inst✝ : DecidableEq α
s : Finset α
f : α → ℤ
n : ℕ
h : ∑ i ∈ s, (f i).natAbs ≤ n
β : Type u
w✝ : Fintype β
sgn : β → SignType
g : β → α
hg : ∀ (b : β), g b ∈ s
hβ : Fintype.card β = ∑ a ∈ s, (f a).natAbs
hf : ∀ a ∈ s, (∑ b, if g b = a then ↑(sgn b) else 0) = f a
⊢ ∃ β x sgn g,
    (∀ (b : β), g b ∉ s → sgn b = 0) ∧ Fintype.card β = n ∧ ∀ a ∈ s, (∑ i, if g i = a then ↑(sgn i) else 0) = f a
Module: Mathlib.Data.EReal.Inv

Goal state before:
pp: case coe.inl
a : ℝ
a_neg : a < 0
⊢ -↑(max |a|⁻¹ 0) = (↑a)⁻¹

Tactic:
max_eq_left (inv_nonneg.2 (abs_nonneg a)),

Goal state after:
case coe.inl
a : ℝ
a_neg : a < 0
⊢ -↑|a|⁻¹ = (↑a)⁻¹
Module: Mathlib.Data.EReal.Inv

Goal state before:
pp: case coe.inr.inr
a : ℝ
a_pos : 0 < a
⊢ ↑(max |a|⁻¹ 0) = (↑a)⁻¹

Tactic:
max_eq_left (inv_nonneg.2 (abs_nonneg a)),

Goal state after:
case coe.inr.inr
a : ℝ
a_pos : 0 < a
⊢ ↑|a|⁻¹ = (↑a)⁻¹
Module: Mathlib.Topology.Semicontinuity.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝² : TopologicalSpace α
f : α → β
inst✝¹ : LinearOrder β
inst✝ : Nonempty β
s : Set α
hs : IsCompact s
hf : LowerSemicontinuousOn f s
⊢ BddBelow (f '' s)

Tactic:
cases s.eq_empty_or_nonempty with
  | inl h =>
      simp only [h, Set.image_empty]
      exact bddBelow_empty
  | inr h =>
      obtain ⟨a, _, has⟩ := LowerSemicontinuousOn.exists_isMinOn h hs hf
      exact has.bddBelow

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

Goal state before:
pp: α : Type u_1
inst✝³ : TopologicalSpace α
γ : Type u_4
inst✝² : LinearOrder γ
inst✝¹ : TopologicalSpace γ
inst✝ : ClosedIciTopology γ
f : α → γ
s : Set α
hs : IsClosed[inst✝³] s
⊢ (∀ x ∈ s, ∀ y < f x, ∀ᶠ (x : α) in 𝓝 x, x ∈ s → y < f x) ↔
    ∀ (x : α × γ), ¬(x.1 ∈ s ∧ f x.1 ≤ x.2) → ∀ᶠ (a : α × γ) in 𝓝 x, ¬(a.1 ∈ s ∧ f a.1 ≤ a.2)

Tactic:
not_and,

Goal state after:
α : Type u_1
inst✝³ : TopologicalSpace α
γ : Type u_4
inst✝² : LinearOrder γ
inst✝¹ : TopologicalSpace γ
inst✝ : ClosedIciTopology γ
f : α → γ
s : Set α
hs : IsClosed[inst✝³] s
⊢ (∀ x ∈ s, ∀ y < f x, ∀ᶠ (x : α) in 𝓝 x, x ∈ s → y < f x) ↔
    ∀ (x : α × γ), (x.1 ∈ s → ¬f x.1 ≤ x.2) → ∀ᶠ (a : α × γ) in 𝓝 x, a.1 ∈ s → ¬f a.1 ≤ a.2
Module: Mathlib.Topology.Instances.EReal.Lemmas

Goal state before:
pp: α : Type u_3
f : Filter α
u : α → EReal
inst✝ : f.NeBot
c : EReal
h₁ : c ≤ 0
h₂ : c ≠ ⊥
⊢ limsup (fun x ↦ c * u x) f = c * liminf u f

Tactic:
by
  simpa [limsup_neg] using
    limsup_const_mul_of_nonneg_of_ne_top (u := -u) (c := -c) (by aesop) (by aesop)

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

Goal state before:
pp: 𝕜 : Type u_4
inst✝⁵ : Field 𝕜
inst✝⁴ : LinearOrder 𝕜
inst✝³ : IsStrictOrderedRing 𝕜
inst✝² : Archimedean 𝕜
inst✝¹ : TopologicalSpace 𝕜
inst✝ : OrderTopology 𝕜
r : 𝕜
h : Tendsto (abs ∘ fun n ↦ r ^ n) atTop (𝓝 0)
hr_le : ¬|r| < 1
hr : ¬1 = |r|
⊢ Tendsto (fun n ↦ |r| ^ n) atTop (𝓝 0)

Tactic:
simpa only [← abs_pow]

Goal state after:
Module: Mathlib.Topology.Instances.EReal.Lemmas

Goal state before:
pp: a b : EReal
h : ContinuousAt (fun p ↦ p.1 * p.2) (a, b)
⊢ (fun p ↦ p.1 * p.2) = (fun x ↦ -x) ∘ (fun p ↦ p.1 * p.2) ∘ fun p ↦ (-p.1, p.2)

Tactic:
ext p

Goal state after:
a b : EReal
h : ContinuousAt (fun p ↦ p.1 * p.2) (a, b)
p : EReal × EReal
⊢ p.1 * p.2 = ((fun x ↦ -x) ∘ (fun p ↦ p.1 * p.2) ∘ fun p ↦ (-p.1, p.2)) p
Module: Mathlib.Topology.Semicontinuity.Basic

Goal state before:
pp: α : Type u_4
β : Type u_5
inst✝¹ : TopologicalSpace α
inst✝ : LinearOrder β
f g : α → β
s : Set α
a : α
hf : LowerSemicontinuousWithinAt f s a
hg : LowerSemicontinuousWithinAt g s a
⊢ LowerSemicontinuousWithinAt (fun x ↦ max (f x) (g x)) s a

Tactic:
by
  intro b hb
  simp only [lt_sup_iff] at hb ⊢
  rcases hb with hb | hb
  · filter_upwards [hf b hb] with x using Or.intro_left _
  · filter_upwards [hg b hb] with x using Or.intro_right _

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

Goal state before:
pp: α : Type u_1
inst✝¹ : TopologicalSpace α
s : Set α
x : α
ι : Sort u_4
δ' : Type u_6
inst✝ : ConditionallyCompleteLinearOrder δ'
f : ι → α → δ'
bdd : ∀ᶠ (y : α) in 𝓝[s] x, BddAbove (range fun i ↦ f i y)
h : ∀ (i : ι), LowerSemicontinuousWithinAt (f i) s x
h✝ : Nonempty ι
y✝ : δ'
hy✝ : (fun x' ↦ ⨆ i, f i x') x > y✝
i : ι
hi : y✝ < f i x
y : α
hy : f i y > y✝
⊢ BddAbove (range fun i ↦ f i y) → ⨆ i, f i y > y✝

Tactic:
hy'

Goal state after:
α : Type u_1
inst✝¹ : TopologicalSpace α
s : Set α
x : α
ι : Sort u_4
δ' : Type u_6
inst✝ : ConditionallyCompleteLinearOrder δ'
f : ι → α → δ'
bdd : ∀ᶠ (y : α) in 𝓝[s] x, BddAbove (range fun i ↦ f i y)
h : ∀ (i : ι), LowerSemicontinuousWithinAt (f i) s x
h✝ : Nonempty ι
y✝ : δ'
hy✝ : (fun x' ↦ ⨆ i, f i x') x > y✝
i : ι
hi : y✝ < f i x
y : α
hy : f i y > y✝
hy' : BddAbove (range fun i ↦ f i y)
⊢ ⨆ i, f i y > y✝
Module: Mathlib.MeasureTheory.PiSystem

Goal state before:
pp: α : Type u_3
ι : Type u_4
π : ι → Set (Set α)
hpi : ∀ (x : ι), IsPiSystem (π x)
S : Set ι
t1 : Set α
p1 : Finset ι
hp1S : ↑p1 ⊆ S
f1 : ι → Set α
hf1m : ∀ x ∈ p1, f1 x ∈ π x
ht1_eq : t1 = ⋂ x ∈ p1, f1 x
t2 : Set α
p2 : Finset ι
hp2S : ↑p2 ⊆ S
f2 : ι → Set α
hf2m : ∀ x ∈ p2, f2 x ∈ π x
ht2_eq : t2 = ⋂ x ∈ p2, f2 x
h_nonempty : (t1 ∩ t2).Nonempty
⊢ ∃ t, ∃ (_ : ↑t ⊆ S), ∃ f, ∃ (_ : ∀ x ∈ t, f x ∈ π x), t1 ∩ t2 = ⋂ x ∈ t, f x

Tactic:
let g n := ite (n ∈ p1) (f1 n) Set.univ ∩ ite (n ∈ p2) (f2 n) Set.univ

Goal state after:
α : Type u_3
ι : Type u_4
π : ι → Set (Set α)
hpi : ∀ (x : ι), IsPiSystem (π x)
S : Set ι
t1 : Set α
p1 : Finset ι
hp1S : ↑p1 ⊆ S
f1 : ι → Set α
hf1m : ∀ x ∈ p1, f1 x ∈ π x
ht1_eq : t1 = ⋂ x ∈ p1, f1 x
t2 : Set α
p2 : Finset ι
hp2S : ↑p2 ⊆ S
f2 : ι → Set α
hf2m : ∀ x ∈ p2, f2 x ∈ π x
ht2_eq : t2 = ⋂ x ∈ p2, f2 x
h_nonempty : (t1 ∩ t2).Nonempty
g : ι → Set α := fun n ↦ (if n ∈ p1 then f1 n else univ) ∩ if n ∈ p2 then f2 n else univ
⊢ ∃ t, ∃ (_ : ↑t ⊆ S), ∃ f, ∃ (_ : ∀ x ∈ t, f x ∈ π x), t1 ∩ t2 = ⋂ x ∈ t, f x
Module: Mathlib.MeasureTheory.MeasurableSpace.Embedding

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g : β → γ
hg : MeasurableEmbedding g
⊢ Measurable (g ∘ f) ↔ Measurable f

Tactic:
refine ⟨fun H => ?_, hg.measurable.comp⟩
  suffices Measurable ((rangeSplitting g ∘ rangeFactorization g) ∘ f) by
    rwa [(rightInverse_rangeSplitting hg.injective).comp_eq_id] at this
  exact hg.measurable_rangeSplitting.comp H.subtype_mk

Goal state after:
Module: Mathlib.MeasureTheory.OuterMeasure.Induced

Goal state before:
pp: α : Type u_1
inst✝¹ : MeasurableSpace α
ι : Sort u_2
inst✝ : Countable ι
μ : ι → OuterMeasure α
s : Set α
t : ι → Set α
ht : ∀ (i : ι), MeasurableSet (t i)
hμt : ∀ (i : ι), (μ i) (t i) = (μ i).trim s
hst : s ⊆ ⋂ i, t i
⊢ ∃ t, s ⊆ t ∧ MeasurableSet t ∧ ∀ (i : ι), (μ i) t = (μ i).trim s

Tactic:
replace ht := MeasurableSet.iInter ht

Goal state after:
α : Type u_1
inst✝¹ : MeasurableSpace α
ι : Sort u_2
inst✝ : Countable ι
μ : ι → OuterMeasure α
s : Set α
t : ι → Set α
hμt : ∀ (i : ι), (μ i) (t i) = (μ i).trim s
hst : s ⊆ ⋂ i, t i
ht : MeasurableSet (⋂ b, t b)
⊢ ∃ t, s ⊆ t ∧ MeasurableSet t ∧ ∀ (i : ι), (μ i) t = (μ i).trim s
Module: Mathlib.MeasureTheory.MeasurableSpace.Embedding

Goal state before:
pp: case inl
α✝ : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α✝
inst✝⁵ : MeasurableSpace α✝
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
π : δ' → Type u_6
π' : δ' → Type u_7
inst✝² : (x : δ') → MeasurableSpace (π x)
inst✝¹ : (x : δ') → MeasurableSpace (π' x)
α : δ ⊕ δ' → Type u_8
inst✝ : (i : δ ⊕ δ') → MeasurableSpace (α i)
i : δ
⊢ Measurable fun x ↦ (Equiv.sumPiEquivProdPi α).symm x (Sum.inl i)

Tactic:
exact measurable_pi_iff.1 measurable_fst _

Goal state after:
Module: Mathlib.MeasureTheory.MeasurableSpace.Embedding

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
inst✝² : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f✝ : α → β
g✝ : β → α
f : α → β
g : β → α
hf : MeasurableEmbedding f
hg : MeasurableEmbedding g
F : Set α → Set α := fun A ↦ (g '' (f '' A)ᶜ)ᶜ
A : Set α
Ameas : MeasurableSet A
Afp : F A = A
B : Set β := f '' A
Bmeas : MeasurableSet B
⊢ Aᶜ = g '' Bᶜ

Tactic:
apply compl_injective

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
inst✝² : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f✝ : α → β
g✝ : β → α
f : α → β
g : β → α
hf : MeasurableEmbedding f
hg : MeasurableEmbedding g
F : Set α → Set α := ⋯
A : Set α
Ameas : MeasurableSet A
Afp : F A = A
B : Set β := ⋯
Bmeas : MeasurableSet B
⊢ Aᶜᶜ = (g '' Bᶜ)ᶜ
Module: Mathlib.MeasureTheory.Measure.NullMeasurable

Goal state before:
pp: ι : Type u_1
α : Type u_2
m0 : MeasurableSpace α
μ : Measure α
inst✝ : Countable ι
f : ι → Set α
hn : Pairwise (Disjoint on f)
h : ∀ (i : ι), MeasurableSet (f i)
⊢ extend (fun t _ht ↦ μ t) (⋃ b, f b) = ∑' (i : ι), μ (f i)

Tactic:
extend_iUnion MeasurableSet.empty _ MeasurableSet.iUnion _ hn h

Goal state after:
ι : Type u_1
α : Type u_2
m0 : MeasurableSpace α
μ : Measure α
inst✝ : Countable ι
f : ι → Set α
hn : Pairwise (Disjoint on f)
h : ∀ (i : ι), MeasurableSet (f i)
⊢ ∑' (i : ι), extend (fun t _ht ↦ μ t) (f i) = ∑' (i : ι), μ (f i)

ι : Type u_1
α : Type u_2
m0 : MeasurableSpace α
μ : Measure α
inst✝ : Countable ι
f : ι → Set α
hn : Pairwise (Disjoint on f)
h : ∀ (i : ι), MeasurableSet (f i)
⊢ μ ∅ = 0

ι : Type u_1
α : Type u_2
m0 : MeasurableSpace α
μ : Measure α
inst✝ : Countable ι
f : ι → Set α
hn : Pairwise (Disjoint on f)
h : ∀ (i : ι), MeasurableSet (f i)
⊢ ∀ ⦃f : ℕ → Set α⦄, (∀ (i : ℕ), MeasurableSet (f i)) → Pairwise (Disjoint on f) → μ (⋃ i, f i) = ∑' (i : ℕ), μ (f i)
Module: Mathlib.MeasureTheory.OuterMeasure.BorelCantelli

Goal state before:
pp: α : Type u_1
ι : Type u_2
F : Type u_3
inst✝² : FunLike F (Set α) ℝ≥0∞
inst✝¹ : OuterMeasureClass F α
inst✝ : Countable ι
μ : F
s : ι → Set α
h : ∑' (i : ι), μ (s i) ≠ ∞
⊢ ∀ᵐ (x : α) ∂μ, {i | x ∈ s i}.Finite

Tactic:
rw [ae_iff, ← measure_limsup_cofinite_eq_zero h]
  congr 1 with x
  simp [mem_limsup_iff_frequently_mem, Filter.Frequently]

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

Goal state before:
pp: α : Type u_1
β : Type u_2
x✝ : MeasurableSpace α
inst✝ : MeasurableSpace β
μ : Measure α
e : α ≃ᵐ β
⊢ Measure.map (⇑e.symm) (Measure.map (⇑e) μ) ≪ μ

Tactic:
Measure.map_map,

Goal state after:
α : Type u_1
β : Type u_2
x✝ : MeasurableSpace α
inst✝ : MeasurableSpace β
μ : Measure α
e : α ≃ᵐ β
⊢ Measure.map (⇑e.symm ∘ ⇑e) μ ≪ μ

case hg
α : Type u_1
β : Type u_2
x✝ : MeasurableSpace α
inst✝ : MeasurableSpace β
μ : Measure α
e : α ≃ᵐ β
⊢ Measurable ⇑e.symm

case hf
α : Type u_1
β : Type u_2
x✝ : MeasurableSpace α
inst✝ : MeasurableSpace β
μ : Measure α
e : α ≃ᵐ β
⊢ Measurable ⇑e
Module: Mathlib.MeasureTheory.Measure.MeasureSpace

Goal state before:
pp: α : Type u_1
ι : Type u_8
x✝ : MeasurableSpace α
μ : Measure α
As : ι → Set α
As_mble : ∀ (i : ι), NullMeasurableSet (As i) μ
As_disj : Pairwise (AEDisjoint μ on As)
⊢ ∑' (i : ι), μ (As i) ≤ μ (⋃ i, As i)

Tactic:
rw [ENNReal.tsum_eq_iSup_sum, iSup_le_iff]

Goal state after:
α : Type u_1
ι : Type u_8
x✝ : MeasurableSpace α
μ : Measure α
As : ι → Set α
As_mble : ∀ (i : ι), NullMeasurableSet (As i) μ
As_disj : Pairwise (AEDisjoint μ on As)
⊢ ∀ (i : Finset ι), ∑ a ∈ i, μ (As a) ≤ μ (⋃ i, As i)