mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Data.QPF.Multivariate.Basic

Goal state before:
pp: n : ℕ
F : TypeVec.{u} n → Type u_1
q : MvQPF F
h : IsUniform
α β : TypeVec.{u} n
g : α ⟹ β
x : F α
i : Fin2 n
a : (P F).A
f : (P F).B a ⟹ α
⊢ (g ⊚ f) i '' univ = g i '' f i '' univ

Tactic:
← image_comp

Goal state after:
n : ℕ
F : TypeVec.{u} n → Type u_1
q : MvQPF F
h : IsUniform
α β : TypeVec.{u} n
g : α ⟹ β
x : F α
i : Fin2 n
a : (P F).A
f : (P F).B a ⟹ α
⊢ (g ⊚ f) i '' univ = g i ∘ f i '' univ
Module: Mathlib.Data.QPF.Multivariate.Constructions.Fix

Goal state before:
pp: n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
β : Type u
g : F (α ::: β) → β
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
⊢ recF g ((P F).wMk a f' f) = g (abs ((TypeVec.id ::: recF g) <$$> (P F).wDest' ((P F).wMk a f' f)))

Tactic:
rw [recF_eq, q.P.wDest'_wMk, MvPFunctor.map_eq, appendFun_comp_splitFun, TypeVec.id_comp]

Goal state after:
Module: Mathlib.Data.Ordmap.Ordset

Goal state before:
pp: case right
α : Type u_1
inst✝¹ : Preorder α
inst✝ : DecidableLE α
x : α
size✝ : ℕ
t_l : Ordnode α
t_x : α
t_r : Ordnode α
a₁ : WithBot α
a₂ : WithTop α
h : Valid' a₁ (Ordnode.node size✝ t_l t_x t_r) a₂
t_l_valid : Valid' a₁ (erase x t_l) ↑t_x
t_l_size : Raised (erase x t_l).size t_l.size
t_r_valid : Valid' (↑t_x) (erase x t_r) a₂
t_r_size : Raised (erase x t_r).size t_r.size
h_balanceable :
  (∃ l', Raised (erase x t_l).size l' ∧ BalancedSz l' t_r.size) ∨
    ∃ r', Raised r' t_r.size ∧ BalancedSz (erase x t_l).size r'
⊢ Raised (erase x t_l).size t_l.size

Tactic:
exact t_l_size

Goal state after:
Module: Mathlib.Data.QPF.Multivariate.Constructions.Fix

Goal state before:
pp: n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
p : Fix F α → Prop
h : ∀ (x : F (α ::: Fix F α)), LiftP (α.PredLast p) x → p (mk x)
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
ih : ∀ (i : (P F).last.B a), p (Quot.mk (⇑(wSetoid α)) (f i))
⊢ LiftP (α.PredLast p) (abs ⟨a, (P F).appendContents f' fun x ↦ ⟦f x⟧⟩)

Tactic:
MvQPF.liftP_iff

Goal state after:
n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
p : Fix F α → Prop
h : ∀ (x : F (α ::: Fix F α)), LiftP (α.PredLast p) x → p (mk x)
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
ih : ∀ (i : (P F).last.B a), p (Quot.mk (⇑(wSetoid α)) (f i))
⊢ ∃ a_1 f_1,
    abs ⟨a, (P F).appendContents f' fun x ↦ ⟦f x⟧⟩ = abs ⟨a_1, f_1⟩ ∧
      ∀ (i : Fin2 (n + 1)) (j : (P F).B a_1 i), α.PredLast p (f_1 i j)
Module: Mathlib.Data.QPF.Univariate.Basic

Goal state before:
pp: F : Type u → Type u
q : QPF F
α : Type u
x : F α
⊢ (∀ (p : α → Prop), Liftp p x ↔ ∀ u ∈ supp x, p u) ↔
    ∃ a f, abs ⟨a, f⟩ = x ∧ ∀ (a' : (P F).A) (f' : (P F).B a' → α), abs ⟨a', f'⟩ = x → f '' univ ⊆ f' '' univ

Tactic:
by
  constructor
  · intro h
    have : Liftp (· ∈ supp x) x := by rw [h]; intro u; exact id
    rw [liftp_iff] at this
    rcases this with ⟨a, f, xeq, h'⟩
    refine ⟨a, f, xeq.symm, ?_⟩
    intro a' f' h''
    rintro u ⟨i, _, hfi⟩
    have : u ∈ supp x := by rw [← hfi]; apply h'
    exact (mem_supp x u).mp this _ _ h''
  rintro ⟨a, f, xeq, h⟩ p; rw [liftp_iff]; constructor
  · rintro ⟨a', f', xeq', h'⟩ u usuppx
    rcases (mem_supp x u).mp usuppx a' f' xeq'.symm with ⟨i, _, f'ieq⟩
    rw [← f'ieq]
    apply h'
  intro h'
  refine ⟨a, f, xeq.symm, ?_⟩; intro i
  apply h'; rw [mem_supp]
  intro a' f' xeq'
  apply h a' f' xeq'
  apply mem_image_of_mem _ (mem_univ _)

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

Goal state before:
pp: α : Type u
a : α
n : ℕ
IH : ∀ {s : WSeq α}, a ∈ s.tail → some (some a) = (↑s.tail).get n → a ∈ s
s : WSeq α
m : a ∈ s.think.tail
e : some (some a) = (↑s.think.tail).get (n + 1)
⊢ a ∈ s.think

Tactic:
simp only [tail_think, mem_think] at m e ⊢

Goal state after:
α : Type u
a : α
n : ℕ
IH : ∀ {s : WSeq α}, a ∈ s.tail → some (some a) = (↑s.tail).get n → a ∈ s
s : WSeq α
m : a ∈ s.tail
e : some (some a) = (↑s.tail.think).get (n + 1)
⊢ a ∈ s
Module: Mathlib.Data.WSeq.Relation

Goal state before:
pp: case nil.nil.cons
α : Type u
SS✝ : WSeq (WSeq (WSeq α))
s1 s2 : WSeq α
h : ∃ s S SS, s1 = s.append (S.append SS.join).join ∧ s2 = s.append (S.join.append (map join SS).join)
c1 c2 : Computation (Option (α × WSeq α))
S : WSeq (WSeq α)
SS : WSeq (WSeq (WSeq α))
⊢ LiftRelAux
    (LiftRelO Eq fun s1 s2 ↦
      ∃ s S SS, s1 = s.append (S.append SS.join).join ∧ s2 = s.append (S.join.append (map join SS).join))
    (fun c1 c2 ↦
      ∃ s S SS,
        c1 = (s.append (S.append SS.join).join).destruct ∧ c2 = (s.append (S.join.append (map join SS).join)).destruct)
    (cons S SS).join.join.destruct.destruct (map join (cons S SS)).join.destruct.destruct

Tactic:
| cons S SS =>

Goal state after:
Module: Mathlib.Data.WSeq.Relation

Goal state before:
pp: case nil
α : Type u
SS✝ : WSeq (WSeq (WSeq α))
s1 s2 : WSeq α
h : ∃ s S SS, s1 = s.append (S.append SS.join).join ∧ s2 = s.append (S.join.append (map join SS).join)
c1 c2 : Computation (Option (α × WSeq α))
S : WSeq (WSeq α)
SS : WSeq (WSeq (WSeq α))
⊢ LiftRelAux
    (LiftRelO Eq fun s1 s2 ↦
      ∃ s S SS, s1 = s.append (S.append SS.join).join ∧ s2 = s.append (S.join.append (map join SS).join))
    (fun c1 c2 ↦
      ∃ s S SS,
        c1 = (s.append (S.append SS.join).join).destruct ∧ c2 = (s.append (S.join.append (map join SS).join)).destruct)
    (nil.append (S.append SS.join).join).destruct.destruct
    (nil.append (S.join.append (map join SS).join)).destruct.destruct

Tactic:
induction S using WSeq.recOn with
        | nil =>
          simp only [nil_append, join_nil]
          induction SS using WSeq.recOn with
          | nil => simp
          | cons S SS => refine ⟨nil, S, SS, ?_, ?_⟩ <;> simp
          | think SS => refine ⟨nil, nil, SS, ?_, ?_⟩ <;> simp
        | cons s S => simpa using ⟨s, S, SS, rfl, rfl⟩
        | think S => refine ⟨nil, S, SS, ?_, ?_⟩ <;> simp

Goal state after:
Module: Mathlib.Data.WSeq.Relation

Goal state before:
pp: α : Type u
β : Type v
γ : Type w
s : WSeq α
f : α → WSeq β
g : β → WSeq γ
⊢ (map (map g ∘ f) s).join.join ~ʷ (map join (map (map g ∘ f) s)).join

Tactic:
exact join_join (map (map g ∘ f) s)

Goal state after:
Module: Mathlib.Data.WSeq.Productive

Goal state before:
pp: α : Type u
s : WSeq α
inst✝ : s.Productive
n : ℕ
⊢ (s.tail.get? n).Terminates

Tactic:
rw [get?_tail]; infer_instance

Goal state after:
Module: Mathlib.Order.SemiconjSup

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : PartialOrder α
inst✝ : Preorder β
fa : α ≃o α
fb : β ↪o β
g : α → β
h : Semiconj g ⇑fa ⇑fb
g' : β → α
hg' : IsOrderRightAdjoint g g'
⊢ Semiconj g' ⇑fb ⇑fa

Tactic:
refine fun y => (hg' _).unique ?_
  rw [← fa.surjective.image_preimage { x | g x ≤ fb y }, preimage_ofPred_eq]
  simp only [h.eq, fb.le_iff_le, fa.isLUB_image'.mpr (hg' _)]

Goal state after:
Module: Mathlib.Dynamics.Circle.RotationNumber.TranslationNumber

Goal state before:
pp: f : CircleDeg1Lift
n : ℕ
this : 0 < 2 ^ (n + 1)
⊢ dist (f.transnumAuxSeq n) (f.transnumAuxSeq (n + 1)) =
    dist ((f ^ 2 ^ n) 0 + (f ^ 2 ^ n) 0) ((f ^ 2 ^ n) ((f ^ 2 ^ n) 0)) / |2 ^ (n + 1)|

Tactic:
transnumAuxSeq,

Goal state after:
f : CircleDeg1Lift
n : ℕ
this : 0 < 2 ^ (n + 1)
⊢ dist ((f ^ 2 ^ n) 0 / 2 ^ n) ((f ^ 2 ^ (n + 1)) 0 / 2 ^ (n + 1)) =
    dist ((f ^ 2 ^ n) 0 + (f ^ 2 ^ n) 0) ((f ^ 2 ^ n) ((f ^ 2 ^ n) 0)) / |2 ^ (n + 1)|
Module: Mathlib.Dynamics.Circle.RotationNumber.TranslationNumber

Goal state before:
pp: case e'_3
f : CircleDeg1Lift
x : ℕ → ℝ
C : ℝ
H : ∀ (n : ℕ), dist ((f ^ n) 0) (x n) ≤ C
n : ℕ
this : 0 < 2 ^ n
⊢ dist (f.transnumAuxSeq n) (x (2 ^ n) / 2 ^ n) = dist ((f ^ 2 ^ n) 0) (x (2 ^ n)) / 2 ^ n

Tactic:
transnumAuxSeq,

Goal state after:
case e'_3
f : CircleDeg1Lift
x : ℕ → ℝ
C : ℝ
H : ∀ (n : ℕ), dist ((f ^ n) 0) (x n) ≤ C
n : ℕ
this : 0 < 2 ^ n
⊢ dist ((f ^ 2 ^ n) 0 / 2 ^ n) (x (2 ^ n) / 2 ^ n) = dist ((f ^ 2 ^ n) 0) (x (2 ^ n)) / 2 ^ n
Module: Mathlib.Dynamics.Circle.RotationNumber.TranslationNumber

Goal state before:
pp: G : Type u_1
inst✝ : Group G
f₁ f₂ : G →* CircleDeg1Lift
h : ∀ (g : G), τ (f₁ g) = τ (f₂ g)
x : ℝ
g : G
this : τ (f₂ g⁻¹) = -τ (f₂ g)
⊢ (f₂ g⁻¹) (x + τ (f₁ g) + 1) = (f₂ g⁻¹) (x + τ (f₂ g)) + 1

Tactic:
rw [h, map_add_one]

Goal state after:
Module: Mathlib.MeasureTheory.Group.AddCircle

Goal state before:
pp: T : ℝ
hT : Fact (0 < T)
I : Set (AddCircle T)
u x : AddCircle T
hu : IsOfFinAddOrder u
G : AddSubgroup (AddCircle T) := AddSubgroup.zmultiples u
n : ℕ := addOrderOf u
B : Set (AddCircle T) := ball x (T / (2 * ↑n))
hI : I =ᵐ[volume] B
hn : 1 ≤ ↑n
g : AddCircle T
hg : g ∈ G
hg' : g ≠ 0
⊢ g +ᵥ B = ball (x + g) (T / (2 * ↑n))

Tactic:
← singleton_add_ball _ x g,

Goal state after:
T : ℝ
hT : Fact (0 < T)
I : Set (AddCircle T)
u x : AddCircle T
hu : IsOfFinAddOrder u
G : AddSubgroup (AddCircle T) := AddSubgroup.zmultiples u
n : ℕ := addOrderOf u
B : Set (AddCircle T) := ball x (T / (2 * ↑n))
hI : I =ᵐ[volume] B
hn : 1 ≤ ↑n
g : AddCircle T
hg : g ∈ G
hg' : g ≠ 0
⊢ g +ᵥ B = {x} + ball g (T / (2 * ↑n))
Module: Mathlib.Topology.Order.CountableSeparating

Goal state before:
pp: case refine_1
X : Type u_1
inst✝³ : TopologicalSpace X
inst✝² : LinearOrder X
inst✝¹ : OrderTopology X
inst✝ : SecondCountableTopology X
s✝ s : Set X
hsc : s.Countable
hsd : Dense s
t : Set X := s ∪ {x | ∃ y, y ⋖ x}
⊢ t.Countable

Tactic:
exact hsc.union countable_setOfPred_covBy_left

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

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν ν' : Measure α
inst✝² : SigmaFinite μ
inst✝¹ : SigmaFinite ν
inst✝ : SigmaFinite ν'
hνν' : ν ⟂ₘ ν'
⊢ μ.rnDeriv (ν + ν') =ᵐ[ν] μ.rnDeriv ν

Tactic:
by
  have h_ac : ν ≪ ν + ν' := Measure.AbsolutelyContinuous.rfl.add_right _
  rw [haveLebesgueDecomposition_add μ ν']
  have h₁ := rnDeriv_add' (μ.singularPart ν') (ν'.withDensity (μ.rnDeriv ν')) (ν + ν')
  have h₂ := rnDeriv_add' (μ.singularPart ν') (ν'.withDensity (μ.rnDeriv ν')) ν
  refine (Filter.EventuallyEq.trans (h_ac.ae_le h₁) ?_).trans h₂.symm
  have h₃ := rnDeriv_add_right_of_mutuallySingular' (?_ : μ.singularPart ν' ⟂ₘ ν') hνν'
  · have h₄ : (ν'.withDensity (rnDeriv μ ν')).rnDeriv (ν + ν') =ᵐ[ν] 0 := by
      refine rnDeriv_eq_zero_of_mutuallySingular ?_ h_ac
      exact hνν'.symm.withDensity
    have h₅ : (ν'.withDensity (rnDeriv μ ν')).rnDeriv ν =ᵐ[ν] 0 := by
      rw [rnDeriv_eq_zero]
      exact hνν'.symm.withDensity
    filter_upwards [h₃, h₄, h₅] with x hx₃ hx₄ hx₅
    rw [Pi.add_apply, Pi.add_apply, hx₃, hx₄, hx₅]
  exact mutuallySingular_singularPart μ ν'

Goal state after:
Module: Mathlib.Dynamics.TopologicalEntropy.CoverEntropy

Goal state before:
pp: X : Type u_1
T : X → X
F : Set X
U : SetRel X X
n : ℕ
h_fin : coverMincard T F U n < ⊤
k : ℕ
k_min : ↑k = ⨅ x, ↑(#↑x)
this : Nonempty { s // IsDynCoverOf T F U n ↑s }
key : ↑k ∈ range fun s ↦ ↑(#↑s)
⊢ ∃ s, IsDynCoverOf T F U n ↑s ∧ #s = k

Tactic:
mem_range,

Goal state after:
X : Type u_1
T : X → X
F : Set X
U : SetRel X X
n : ℕ
h_fin : coverMincard T F U n < ⊤
k : ℕ
k_min : ↑k = ⨅ x, ↑(#↑x)
this : Nonempty { s // IsDynCoverOf T F U n ↑s }
key : ∃ y, ↑(#↑y) = ↑k
⊢ ∃ s, IsDynCoverOf T F U n ↑s ∧ #s = k
Module: Mathlib.Dynamics.TopologicalEntropy.Semiconj

Goal state before:
pp: case a
X : Type u_1
Y : Type u_2
u : UniformSpace Y
S : X → X
T : Y → Y
φ : X → Y
h : Semiconj φ S T
F : Set X
this : UniformSpace X := ⋯
⊢ coverEntropyInf S F ≤ coverEntropyInf T (φ '' F)

Tactic:
refine iSup₂_le fun U U_uni ↦ ?_
    simp only [uniformity_comap φ, mem_comap] at U_uni
    obtain ⟨V, V_uni, V_sub⟩ := U_uni
    obtain ⟨W, W_uni, W_symm, W_V⟩ := comp_symm_mem_uniformity_sets V_uni
    apply (coverEntropyInfEntourage_antitone S F ((preimage_mono W_V).trans V_sub)).trans
    apply (le_coverEntropyInfEntourage_image h F).trans
    exact coverEntropyInfEntourage_le_coverEntropyInf T (φ '' F) W_uni

Goal state after:
Module: Mathlib.Dynamics.TopologicalEntropy.NetEntropy

Goal state before:
pp: X : Type u_1
T : X → X
F : Set X
h : F.Nonempty
⊢ netEntropyInfEntourage T F univ = 0

Tactic:
by
  rw [← expGrowthInf_const one_ne_zero one_ne_top, netEntropyInfEntourage]
  simp only [netMaxcard_univ T h, ENat.toENNReal_one]

Goal state after:
Module: Mathlib.FieldTheory.AbelRuffini

Goal state before:
pp: case neg
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : X ^ n - C a ≠ 0
hn''' : X ^ n - 1 ≠ 0
mem_range : ∀ {c : (X ^ n - C a).SplittingField}, c ^ n = 1 → ∃ d, (algebraMap F (X ^ n - C a).SplittingField) d = c
σ τ : (X ^ n - C a).Gal
b : (X ^ n - C a).SplittingField
hb : b ^ n = (algebraMap F (X ^ n - C a).SplittingField) a
hb' : b ≠ 0
key : ∀ (σ : (X ^ n - C a).Gal), ∃ c, σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
c : F
hc : σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
d : F
hd : τ b = b * (algebraMap F (X ^ n - C a).SplittingField) d
⊢ σ (τ b) = τ (b * (algebraMap F (X ^ n - C a).SplittingField) c)

Tactic:
map_mul,

Goal state after:
case neg
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : X ^ n - C a ≠ 0
hn''' : X ^ n - 1 ≠ 0
mem_range : ∀ {c : (X ^ n - C a).SplittingField}, c ^ n = 1 → ∃ d, (algebraMap F (X ^ n - C a).SplittingField) d = c
σ τ : (X ^ n - C a).Gal
b : (X ^ n - C a).SplittingField
hb : b ^ n = (algebraMap F (X ^ n - C a).SplittingField) a
hb' : b ≠ 0
key : ∀ (σ : (X ^ n - C a).Gal), ∃ c, σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
c : F
hc : σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
d : F
hd : τ b = b * (algebraMap F (X ^ n - C a).SplittingField) d
⊢ σ (τ b) = τ b * τ ((algebraMap F (X ^ n - C a).SplittingField) c)
Module: Mathlib.FieldTheory.AbelRuffini

Goal state before:
pp: case neg
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : X ^ n - C a ≠ 0
hn''' : X ^ n - 1 ≠ 0
mem_range : ∀ {c : (X ^ n - C a).SplittingField}, c ^ n = 1 → ∃ d, (algebraMap F (X ^ n - C a).SplittingField) d = c
σ τ : (X ^ n - C a).Gal
b : (X ^ n - C a).SplittingField
hb : b ^ n = (algebraMap F (X ^ n - C a).SplittingField) a
hb' : b ≠ 0
key : ∀ (σ : (X ^ n - C a).Gal), ∃ c, σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
c : F
hc : σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
d : F
hd : τ b = b * (algebraMap F (X ^ n - C a).SplittingField) d
⊢ σ (τ b) = τ b * τ ((algebraMap F (X ^ n - C a).SplittingField) c)

Tactic:
τ.commutes,

Goal state after:
case neg
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : X ^ n - C a ≠ 0
hn''' : X ^ n - 1 ≠ 0
mem_range : ∀ {c : (X ^ n - C a).SplittingField}, c ^ n = 1 → ∃ d, (algebraMap F (X ^ n - C a).SplittingField) d = c
σ τ : (X ^ n - C a).Gal
b : (X ^ n - C a).SplittingField
hb : b ^ n = (algebraMap F (X ^ n - C a).SplittingField) a
hb' : b ≠ 0
key : ∀ (σ : (X ^ n - C a).Gal), ∃ c, σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
c : F
hc : σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
d : F
hd : τ b = b * (algebraMap F (X ^ n - C a).SplittingField) d
⊢ σ (τ b) = τ b * (algebraMap F (X ^ n - C a).SplittingField) c
Module: Mathlib.FieldTheory.AbelRuffini

Goal state before:
pp: case neg
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : X ^ n - C a ≠ 0
hn''' : X ^ n - 1 ≠ 0
mem_range : ∀ {c : (X ^ n - C a).SplittingField}, c ^ n = 1 → ∃ d, (algebraMap F (X ^ n - C a).SplittingField) d = c
σ τ : (X ^ n - C a).Gal
b : (X ^ n - C a).SplittingField
hb : b ^ n = (algebraMap F (X ^ n - C a).SplittingField) a
hb' : b ≠ 0
key : ∀ (σ : (X ^ n - C a).Gal), ∃ c, σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
c : F
hc : σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
d : F
hd : τ b = b * (algebraMap F (X ^ n - C a).SplittingField) d
⊢ σ (b * (algebraMap F (X ^ n - C a).SplittingField) d) =
    b * (algebraMap F (X ^ n - C a).SplittingField) d * (algebraMap F (X ^ n - C a).SplittingField) c

Tactic:
map_mul,

Goal state after:
case neg
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : X ^ n - C a ≠ 0
hn''' : X ^ n - 1 ≠ 0
mem_range : ∀ {c : (X ^ n - C a).SplittingField}, c ^ n = 1 → ∃ d, (algebraMap F (X ^ n - C a).SplittingField) d = c
σ τ : (X ^ n - C a).Gal
b : (X ^ n - C a).SplittingField
hb : b ^ n = (algebraMap F (X ^ n - C a).SplittingField) a
hb' : b ≠ 0
key : ∀ (σ : (X ^ n - C a).Gal), ∃ c, σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
c : F
hc : σ b = b * (algebraMap F (X ^ n - C a).SplittingField) c
d : F
hd : τ b = b * (algebraMap F (X ^ n - C a).SplittingField) d
⊢ σ b * σ ((algebraMap F (X ^ n - C a).SplittingField) d) =
    b * (algebraMap F (X ^ n - C a).SplittingField) d * (algebraMap F (X ^ n - C a).SplittingField) c
Module: Mathlib.ModelTheory.LanguageMap

Goal state before:
pp: L : Language
L' : Language
ϕ : L →ᴸ L'
inst✝³ : (n : ℕ) → (f : L'.Functions n) → Decidable (f ∈ Set.range fun f ↦ ϕ.onFunction f)
inst✝² : (n : ℕ) → (r : L'.Relations n) → Decidable (r ∈ Set.range fun r ↦ ϕ.onRelation r)
h : ϕ.Injective
M : Type u_1
inst✝¹ : Inhabited M
inst✝ : L.Structure M
⊢ ϕ.IsExpansionOn M

Tactic:
let := ϕ.defaultExpansion M

Goal state after:
L : Language
L' : Language
ϕ : L →ᴸ L'
inst✝³ : (n : ℕ) → (f : L'.Functions n) → Decidable (f ∈ Set.range fun f ↦ ϕ.onFunction f)
inst✝² : (n : ℕ) → (r : L'.Relations n) → Decidable (r ∈ Set.range fun r ↦ ϕ.onRelation r)
h : ϕ.Injective
M : Type u_1
inst✝¹ : Inhabited M
inst✝ : L.Structure M
this : L'.Structure M := ϕ.defaultExpansion M
⊢ ϕ.IsExpansionOn M
Module: Mathlib.FieldTheory.IsAlgClosed.Classification

Goal state before:
pp: case inr
K : Type u
L : Type v
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : IsAlgClosed K
inst✝² : IsAlgClosed L
p : ℕ
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
inst✝¹ : CharP K 0
inst✝ : CharP L 0
hp : True
this✝ : CharZero K := CharP.charP_to_charZero K
this : CharZero L := CharP.charP_to_charZero L
⊢ Nonempty (K ≃+* L)

Tactic:
exact ringEquiv_of_equiv_of_charZero hK hKL

Goal state after:
Module: Mathlib.FieldTheory.AbelRuffini

Goal state before:
pp: F : Type u_1
E : Type u_2
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
x y z : E
hx : x ∈ solvableByRad F E
hy : y ∈ solvableByRad F E
hz : z ∈ solvableByRad F E
hx' : Group.IsSolvable (minpoly F x).Gal
hy' : Group.IsSolvable (minpoly F y).Gal
hz' : z ∈ F⟮x, y⟯
p : F[X] := minpoly F x
q : F[X] := minpoly F y
hpq :
  (Polynomial.map (algebraMap F (p * q).SplittingField) (minpoly F x)).Splits ∧
    (Polynomial.map (algebraMap F (p * q).SplittingField) (minpoly F y)).Splits
f : ↥F⟮x, y⟯ →ₐ[F] (p * q).SplittingField
⊢ minpoly F z = minpoly F (f ⟨z, hz'⟩)

Tactic:
refine minpoly.eq_of_irreducible_of_monic
      (minpoly.irreducible (isIntegral_of_mem_solvableByRad hz)) ?_
      (minpoly.monic (isIntegral_of_mem_solvableByRad hz))

Goal state after:
F : Type u_1
E : Type u_2
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
x y z : E
hx : x ∈ solvableByRad F E
hy : y ∈ solvableByRad F E
hz : z ∈ solvableByRad F E
hx' : Group.IsSolvable (minpoly F x).Gal
hy' : Group.IsSolvable (minpoly F y).Gal
hz' : z ∈ F⟮x, y⟯
p : F[X] := minpoly F x
q : F[X] := minpoly F y
hpq :
  (Polynomial.map (algebraMap F (p * q).SplittingField) (minpoly F x)).Splits ∧
    (Polynomial.map (algebraMap F (p * q).SplittingField) (minpoly F y)).Splits
f : ↥F⟮x, y⟯ →ₐ[F] (p * q).SplittingField
⊢ (aeval (f ⟨z, hz'⟩)) (minpoly F z) = 0
Module: Mathlib.ModelTheory.Semantics

Goal state before:
pp: L : Language
M : Type w
inst✝ : L.Structure M
T T' : L.Theory
h : M ⊨ T
h' : M ⊨ T'
⊢ M ⊨ T ∪ T'

Tactic:
by
  simp only [model_iff, Set.mem_union] at *
  exact fun φ hφ => hφ.elim (h _) (h' _)

Goal state after:
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
M : Type w'
inst✝ : L.Structure M
iM : Infinite M
κ : Cardinal.{w}
h1 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
h2 : lift.{max w u v, w'} #M ≤ lift.{max w' u v, w} κ
N0 : (L.elementaryDiagram M).ModelType
hN0 : lift.{max (max u w') v w, w} κ ≤ #↑N0
⊢ ∃ N, Nonempty (M ↪ₑ[L] ↑N) ∧ #↑N = κ

Tactic:
obtain ⟨N, ⟨NN0⟩, hN⟩ :=
    exists_elementaryEmbedding_card_eq_of_le L[[M]] N0 κ
      (aleph0_le_lift.1 ((aleph0_le_lift.2 (aleph0_le_mk M)).trans h2))
      (by
        simp only [card_withConstants, lift_add, lift_lift]
        rw [add_comm, add_eq_max (aleph0_le_lift.2 (infinite_iff.1 iM)), max_le_iff]
        rw [← lift_le.{w'}, lift_lift, lift_lift] at h1
        exact ⟨h2, h1⟩)
      (hN0.trans (by rw [← lift_umax, lift_id]))

Goal state after:
L : Language
M : Type w'
inst✝ : L.Structure M
iM : Infinite M
κ : Cardinal.{w}
h1 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
h2 : lift.{max w u v, w'} #M ≤ lift.{max w' u v, w} κ
N0 : (L.elementaryDiagram M).ModelType
hN0 : lift.{max (max u w') v w, w} κ ≤ #↑N0
N : Bundled L[[M]].Structure
hN : #↑N = κ
NN0 : ↑N ↪ₑ[L[[M]]] ↑N0
⊢ ∃ N, Nonempty (M ↪ₑ[L] ↑N) ∧ #↑N = κ
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
κ : Cardinal.{w}
T : L.Theory
h : κ.Categorical T
h1 : ℵ₀ ≤ κ
h2 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
hS : T.IsSatisfiable
hT : ∀ (M : T.ModelType), Infinite ↑M
φ : L.Sentence
⊢ T ⊨ᵇ φ ∨ T ⊨ᵇ Formula.not φ

Tactic:
obtain ⟨_, _⟩ := Theory.exists_model_card_eq ⟨hS.some, hT hS.some⟩ κ h1 h2

Goal state after:
L : Language
κ : Cardinal.{w}
T : L.Theory
h : κ.Categorical T
h1 : ℵ₀ ≤ κ
h2 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
hS : T.IsSatisfiable
hT : ∀ (M : T.ModelType), Infinite ↑M
φ : L.Sentence
w✝ : T.ModelType
h✝ : #↑w✝ = κ
⊢ T ⊨ᵇ φ ∨ T ⊨ᵇ Formula.not φ
Module: Mathlib.FieldTheory.Finite.Extension

Goal state before:
pp: k : Type u_1
inst✝⁶ : Field k
inst✝⁵ : Finite k
p : ℕ
inst✝⁴ : Fact (Nat.Prime p)
inst✝³ : CharP k p
n : ℕ
inst✝² : NeZero n
l : Type u_2
inst✝¹ : Field l
inst✝ : Algebra k l
h : Module.finrank k l = n
⊢ l ≃ₐ[k] Extension k p n

Tactic:
refine Nonempty.some ?_

Goal state after:
k : Type u_1
inst✝⁶ : Field k
inst✝⁵ : Finite k
p : ℕ
inst✝⁴ : Fact (Nat.Prime p)
inst✝³ : CharP k p
n : ℕ
inst✝² : NeZero n
l : Type u_2
inst✝¹ : Field l
inst✝ : Algebra k l
h : Module.finrank k l = n
⊢ Nonempty (l ≃ₐ[k] Extension k p n)
Module: Mathlib.FieldTheory.Finite.Polynomial

Goal state before:
pp: case intro
K : Type u_1
σ : Type u_2
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : Finite σ
val✝ : Fintype σ
e : (σ → K) → K
x✝ : e ∈ ⊤
⊢ ∃ y ∈ restrictDegree σ K (Fintype.card K - 1), (evalₗ K σ) y = e

Tactic:
refine ⟨∑ n : σ → K, e n • indicator n, ?_, ?_⟩

Goal state after:
case intro.refine_1
K : Type u_1
σ : Type u_2
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : Finite σ
val✝ : Fintype σ
e : (σ → K) → K
x✝ : e ∈ ⊤
⊢ ∑ n, e n • indicator n ∈ restrictDegree σ K (Fintype.card K - 1)

case intro.refine_2
K : Type u_1
σ : Type u_2
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : Finite σ
val✝ : Fintype σ
e : (σ → K) → K
x✝ : e ∈ ⊤
⊢ (evalₗ K σ) (∑ n, e n • indicator n) = e
Module: Mathlib.FieldTheory.Differential.Liouville

Goal state before:
pp: case a
F : Type u_1
K : Type u_2
inst✝⁸ : Field F
inst✝⁷ : Field K
inst✝⁶ : Differential F
inst✝⁵ : Differential K
inst✝⁴ : Algebra F K
inst✝³ : DifferentialAlgebra F K
inst✝² : CharZero F
B : IntermediateField F K
inst✝¹ : FiniteDimensional F ↥B
inst : IsLiouville F K
a : F
ι : Type
inst✝ : Fintype ι
c : ι → F
hc : ∀ (x : ι), (c x)′ = 0
u : ι → ↥B
v : ↥B
h : ↑a = ∑ x, ↑(c x) * logDeriv (u x) + v′
| (↑v)′

Tactic:
· apply (deriv_algebraMap v)

Goal state after:
Module: Mathlib.FieldTheory.IsPerfectClosure

Goal state before:
pp: R : Type u_1
inst✝ : CommSemiring R
p : ℕ
x : R
hp : ¬1 < p
h : x = 0
⊢ x ^ p ^ 0 = 0

Tactic:
by rw [pow_zero, pow_one, h]

Goal state after: