mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.FieldTheory.Finite.Polynomial

Goal state before:
pp: K : Type u_1
σ : Type u_2
inst✝² : Fintype K
inst✝¹ : Fintype σ
inst✝ : CommRing K
c : σ → K
n : σ
⊢ ∑ x, (Fintype.card K - 1) • Multiset.count n {x} = Fintype.card K - 1

Tactic:
nsmul_eq_mul,

Goal state after:
K : Type u_1
σ : Type u_2
inst✝² : Fintype K
inst✝¹ : Fintype σ
inst✝ : CommRing K
c : σ → K
n : σ
⊢ ∑ x, ↑(Fintype.card K - 1) * Multiset.count n {x} = Fintype.card K - 1
Module: Mathlib.FieldTheory.Finite.Polynomial

Goal state before:
pp: K : Type u_1
σ : Type u_2
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : Finite σ
⊢ Submodule.map (evalₗ K σ) (restrictDegree σ K (Fintype.card K - 1)) = ⊤

Tactic:
by
  cases nonempty_fintype σ
  refine top_unique (SetLike.le_def.2 fun e _ => mem_map.2 ?_)
  classical
  refine ⟨∑ n : σ → K, e n • indicator n, ?_, ?_⟩
  · exact sum_mem fun c _ => smul_mem _ _ (indicator_mem_restrictDegree _)
  · ext n
    simp only [evalₗ_apply, map_sum, smul_eval]
    rw [Finset.sum_eq_single n] <;>
      aesop (add simp [eval_indicator_apply_eq_zero, eval_indicator_apply_eq_one, eq_comm])

Goal state after:
Module: Mathlib.FieldTheory.Differential.Liouville

Goal state before:
pp: case refine_2
F : Type u_1
K : Type u_2
inst✝⁹ : Field F
inst✝⁸ : Field K
inst✝⁷ : Differential F
inst✝⁶ : Differential K
inst✝⁵ : Algebra F K
inst✝⁴ : DifferentialAlgebra F K
inst✝³ : CharZero F
inst✝² : FiniteDimensional F K
inst✝¹ : IsGalois F K
a : F
ι : Type
inst✝ : Fintype ι
c : ι → F
hc : ∀ (x : ι), (c x)′ = 0
u : ι → K
v : K
h : ↑a = ∑ x, ↑(c x) * logDeriv (u x) + v′
this : CharZero K
c₀ : ι → F := fun i ↦ c i / ↑(Fintype.card Gal(K/F))
u₁ : ι → K := fun i ↦ ∏ x, x (u i)
ffb : fixedField ⊤ = ⊥
u₀ : ι → F
hu₀ : ∀ (i : ι), (algebraMap F K) (u₀ i) = u₁ i
v₁ : K := (∑ x, x v) / ↑(Fintype.card Gal(K/F))
v₀ : F
hv₀ : (algebraMap F K) v₀ = v₁
⊢ a = ∑ x, c₀ x * logDeriv (u₀ x) + v₀′

Tactic:
apply_fun (algebraMap F K)

Goal state after:
case refine_2
F : Type u_1
K : Type u_2
inst✝⁹ : Field F
inst✝⁸ : Field K
inst✝⁷ : Differential F
inst✝⁶ : Differential K
inst✝⁵ : Algebra F K
inst✝⁴ : DifferentialAlgebra F K
inst✝³ : CharZero F
inst✝² : FiniteDimensional F K
inst✝¹ : IsGalois F K
a : F
ι : Type
inst✝ : Fintype ι
c : ι → F
hc : ∀ (x : ι), (c x)′ = 0
u : ι → K
v : K
h : ↑a = ∑ x, ↑(c x) * logDeriv (u x) + v′
this : CharZero K
c₀ : ι → F := fun i ↦ c i / ↑(Fintype.card Gal(K/F))
u₁ : ι → K := fun i ↦ ∏ x, x (u i)
ffb : fixedField ⊤ = ⊥
u₀ : ι → F
hu₀ : ∀ (i : ι), (algebraMap F K) (u₀ i) = u₁ i
v₁ : K := (∑ x, x v) / ↑(Fintype.card Gal(K/F))
v₀ : F
hv₀ : (algebraMap F K) v₀ = v₁
⊢ (algebraMap F K) a = (algebraMap F K) (∑ x, c₀ x * logDeriv (u₀ x) + v₀′)

case refine_2.inj
F : Type u_1
K : Type u_2
inst✝⁹ : Field F
inst✝⁸ : Field K
inst✝⁷ : Differential F
inst✝⁶ : Differential K
inst✝⁵ : Algebra F K
inst✝⁴ : DifferentialAlgebra F K
inst✝³ : CharZero F
inst✝² : FiniteDimensional F K
inst✝¹ : IsGalois F K
a : F
ι : Type
inst✝ : Fintype ι
c : ι → F
hc : ∀ (x : ι), (c x)′ = 0
u : ι → K
v : K
h : ↑a = ∑ x, ↑(c x) * logDeriv (u x) + v′
this : CharZero K
c₀ : ι → F := fun i ↦ c i / ↑(Fintype.card Gal(K/F))
u₁ : ι → K := fun i ↦ ∏ x, x (u i)
ffb : fixedField ⊤ = ⊥
u₀ : ι → F
hu₀ : ∀ (i : ι), (algebraMap F K) (u₀ i) = u₁ i
v₁ : K := (∑ x, x v) / ↑(Fintype.card Gal(K/F))
v₀ : F
hv₀ : (algebraMap F K) v₀ = v₁
⊢ Function.Injective ⇑(algebraMap F K)
Module: Mathlib.FieldTheory.Galois.NormalBasis

Goal state before:
pp: case e'_4
K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Finite L
this✝ : Finite K
this : Fintype K
x : L
hx :
  Ideal.span {X ^ finrank K L - 1} =
    (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
        ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x)).ker
e_1✝ : Fin (X ^ finrank K L - C 1).natDegree = Fin (AdjoinRoot.powerBasis ⋯).dim
i : Fin (X ^ finrank K L - C 1).natDegree
⊢ ((Equiv.ofBijective (fun n ↦ frobeniusAlgEquivOfAlgebraic K L ^ ↑n) ⋯) (Fin.cast ⋯ i)) x =
    (↑(AEval'.of (frobeniusAlgHom K L).toLinearMap).symm ∘ₗ
        ↑K
          (liftQ (Ideal.span {X ^ finrank K L - 1})
            (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
              ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x))
            ⋯))
      ((AdjoinRoot.powerBasis ⋯).basis i)

Tactic:
Equiv.ofBijective_apply,

Goal state after:
case e'_4
K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Finite L
this✝ : Finite K
this : Fintype K
x : L
hx :
  Ideal.span {X ^ finrank K L - 1} =
    (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
        ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x)).ker
e_1✝ : Fin (X ^ finrank K L - C 1).natDegree = Fin (AdjoinRoot.powerBasis ⋯).dim
i : Fin (X ^ finrank K L - C 1).natDegree
⊢ (frobeniusAlgEquivOfAlgebraic K L ^ ↑(Fin.cast ⋯ i)) x =
    (↑(AEval'.of (frobeniusAlgHom K L).toLinearMap).symm ∘ₗ
        ↑K
          (liftQ (Ideal.span {X ^ finrank K L - 1})
            (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
              ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x))
            ⋯))
      ((AdjoinRoot.powerBasis ⋯).basis i)
Module: Mathlib.FieldTheory.PerfectClosure

Goal state before:
pp: case mp.rel
K : Type u
inst✝² : CommRing K
p : ℕ
inst✝¹ : Fact (Nat.Prime p)
inst✝ : CharP K p
x✝ y✝ x y : ℕ × K
H : R K p x y
⊢ ∃ z, (⇑(frobenius K p))^[y.1 + z] x.2 = (⇑(frobenius K p))^[x.1 + z] y.2

Tactic:
obtain ⟨n, x⟩ := H; exact ⟨0, rfl⟩

Goal state after:
Module: Mathlib.Topology.Algebra.Category.ProfiniteGrp.Basic

Goal state before:
pp: J : Type v
inst✝ : SmallCategory J
F : J ⥤ ProfiniteGrp.{max v u}
i j : J
f : i ⟶ j
⊢ ((Functor.const J).obj (ofProfinite (Profinite.limitCone (F ⋙ forget₂ ProfiniteGrp.{max u v} Profinite)).pt)).map f ≫
      { hom' := { toFun := fun x ↦ ↑x j, map_one' := ⋯, map_mul' := ⋯, continuous_toFun := ⋯ } } =
    { hom' := { toFun := fun x ↦ ↑x i, map_one' := ⋯, map_mul' := ⋯, continuous_toFun := ⋯ } } ≫ F.map f

Tactic:
simp only [Functor.const_obj_obj, Functor.comp_obj,
        Functor.const_obj_map, Category.id_comp, Functor.comp_map]
      congr
      exact funext fun x => (x.2 f).symm

Goal state after:
Module: Mathlib.FieldTheory.PerfectClosure

Goal state before:
pp: K : Type u
inst✝² : Field K
p : ℕ
inst✝¹ : Fact (Nat.Prime p)
inst✝ : CharP K p
e : PerfectClosure K p
x✝ : ℕ × K
m : ℕ
x : K
H : mk K p (m, x) ≠ 0
⊢ mk K p (m, x) * (mk K p (m, x))⁻¹ = 1

Tactic:
have := mt (eq_iff _ _ _ _).2 H

Goal state after:
K : Type u
inst✝² : Field K
p : ℕ
inst✝¹ : Fact (Nat.Prime p)
inst✝ : CharP K p
e : PerfectClosure K p
x✝ : ℕ × K
m : ℕ
x : K
H : mk K p (m, x) ≠ 0
this : ¬(⇑(frobenius K p))^[(0, 0).1] (m, x).2 = (⇑(frobenius K p))^[(m, x).1] (0, 0).2
⊢ mk K p (m, x) * (mk K p (m, x))⁻¹ = 1
Module: Mathlib.GroupTheory.CosetCover

Goal state before:
pp: G : Type u_1
inst✝¹ : Group G
D H : Subgroup G
inst✝ : D.FiniteIndex
hD_le_H : D ≤ H
⊢ ∃ t, IsComplement ↑t ↑(D.subgroupOf H) ∧ ⋃ g ∈ t, ↑g • ↑D = ↑H

Tactic:
by
  have ⟨t, ht⟩ := (D.subgroupOf H).exists_isComplement_left 1
  have hf : t.Finite := ht.1.finite_left_iff.mpr inferInstance
  refine ⟨hf.toFinset, hf.coe_toFinset.symm ▸ ht.1, ?_⟩
  ext x
  suffices (∃ y ∈ t, ∃ d ∈ D, y * d = x) ↔ x ∈ H by simpa using! this
  constructor
  · rintro ⟨⟨y, hy⟩, -, d, h, rfl⟩
    exact H.mul_mem hy (hD_le_H h)
  · intro hx
    exact ⟨_, (ht.1.toLeftFun ⟨x, hx⟩).2, _,
      ht.1.inv_toLeftFun_mul_mem ⟨x, hx⟩, mul_inv_cancel_left _ _⟩

Goal state after:
Module: Mathlib.GroupTheory.CosetCover

Goal state before:
pp: G : Type u_1
inst✝¹ : Group G
inst✝ : DecidableEq (Subgroup G)
n : ℕ
ih :
  ∀ m < n,
    ∀ {ι : Type u_2} {H : ι → Subgroup G} {g : ι → G} {s : Finset ι},
      ⋃ i ∈ s, g i • ↑(H i) = Set.univ →
        ∀ j ∈ s,
          ⋃ i ∈ {x ∈ s | H x = H j}, g i • ↑(H i) ≠ Set.univ →
            m = (Finset.image H s).card → ∃ i ∈ s, H i ≠ H j ∧ (H i).FiniteIndex
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
hcovers : ⋃ i ∈ s, g i • ↑(H i) = Set.univ
j : ι
hj : j ∈ s
hcovers' : ⋃ i ∈ {x ∈ s | H x = H j}, g i • ↑(H i) ≠ Set.univ
hn : n = (Finset.image H s).card
x : G
hx : ∀ (y : G), y • ↑(H j) ⊆ ⋃ i ∈ {x ∈ s | H x ≠ H j}, (y * x⁻¹ * g i) • ↑(H i)
κ : Type u_2 := ↥({x ∈ s | H x ≠ H j}) × Option ↥({x ∈ s | H x = H j})
f : κ → G :=
  fun x_1 ↦
    match x_1 with
    | (k₁, some k₂) => g ↑k₂ * x⁻¹ * g ↑k₁
    | (k₁, none) => g ↑k₁
K : κ → Subgroup G := fun k ↦ H ↑k.1
hK' : ∀ (k : κ), K k ∈ (Finset.image H s).erase (H j)
hK : ∀ (k : κ), K k ≠ H j
y : G
⊢ ∃ i, ∃ (_ : i ∈ Finset.univ), y ∈ f i • ↑(K i)

Tactic:
rw [← s.filter_union_filter_not_eq (H · = H j), Finset.set_biUnion_union] at hcovers

Goal state after:
G : Type u_1
inst✝¹ : Group G
inst✝ : DecidableEq (Subgroup G)
n : ℕ
ih :
  ∀ m < n,
    ∀ {ι : Type u_2} {H : ι → Subgroup G} {g : ι → G} {s : Finset ι},
      ⋃ i ∈ s, g i • ↑(H i) = Set.univ →
        ∀ j ∈ s,
          ⋃ i ∈ {x ∈ s | H x = H j}, g i • ↑(H i) ≠ Set.univ →
            m = (Finset.image H s).card → ∃ i ∈ s, H i ≠ H j ∧ (H i).FiniteIndex
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
j : ι
hcovers : (⋃ x ∈ {x ∈ s | H x = H j}, g x • ↑(H x)) ∪ ⋃ x ∈ {a ∈ s | ¬H a = H j}, g x • ↑(H x) = Set.univ
hj : j ∈ s
hcovers' : ⋃ i ∈ {x ∈ s | H x = H j}, g i • ↑(H i) ≠ Set.univ
hn : n = (Finset.image H s).card
x : G
hx : ∀ (y : G), y • ↑(H j) ⊆ ⋃ i ∈ {x ∈ s | H x ≠ H j}, (y * x⁻¹ * g i) • ↑(H i)
κ : Type u_2 := ↥({x ∈ s | H x ≠ H j}) × Option ↥({x ∈ s | H x = H j})
f : κ → G :=
  fun x_1 ↦
    match x_1 with
    | (k₁, some k₂) => g ↑k₂ * x⁻¹ * g ↑k₁
    | (k₁, none) => g ↑k₁
K : κ → Subgroup G := fun k ↦ H ↑k.1
hK' : ∀ (k : κ), K k ∈ (Finset.image H s).erase (H j)
hK : ∀ (k : κ), K k ≠ H j
y : G
⊢ ∃ i, ∃ (_ : i ∈ Finset.univ), y ∈ f i • ↑(K i)
Module: Mathlib.FieldTheory.MvRatFunc.Rank

Goal state before:
pp: case refine_2
σ : Type u
F : Type v
inst✝¹ : Field F
inst✝ : Nonempty σ
R : Type (max v u) := MvPolynomial σ F
K : Type (max u v) := FractionRing R
⊢ max (max (lift.{u, v} #F) (lift.{v, u} #σ)) ℵ₀ ≤ Module.rank F (FractionRing (MvPolynomial σ F))

Tactic:
have hinj := IsFractionRing.injective R K

Goal state after:
case refine_2
σ : Type u
F : Type v
inst✝¹ : Field F
inst✝ : Nonempty σ
R : Type (max v u) := MvPolynomial σ F
K : Type (max u v) := FractionRing R
hinj : Function.Injective ⇑(algebraMap R K)
⊢ max (max (lift.{u, v} #F) (lift.{v, u} #σ)) ℵ₀ ≤ Module.rank F (FractionRing (MvPolynomial σ F))
Module: Mathlib.GroupTheory.CosetCover

Goal state before:
pp: G : Type u_1
inst✝¹ : Group G
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
inst✝ : DecidablePred FiniteIndex
hcovers : ⋃ i ∈ {i ∈ s | (H i).FiniteIndex} ∪ {a ∈ s | ¬(H a).FiniteIndex}, g i • ↑(H i) = Set.univ
D : Subgroup G := ⨅ k ∈ {i ∈ s | (H i).FiniteIndex}, H k
hD : D.FiniteIndex
hD_le : ∀ {i : ι}, i ∈ s → (H i).FiniteIndex → D ≤ H i
t : (i : ι) → i ∈ s → (H i).FiniteIndex → Finset ↥(H i)
ht :
  ∀ (i : ι) (hi : i ∈ s) (hfi : (H i).FiniteIndex),
    IsComplement ↑(t i hi hfi) ↑(D.subgroupOf (H i)) ∧ ⋃ g ∈ t i hi hfi, ↑g • ↑D = ↑(H i)
κ : Type (max u_2 u_1) := (i : ↥s) × ↥(if h : (H ↑i).FiniteIndex then t ↑i ⋯ h else {1})
f : κ → G := fun k ↦ g ↑k.fst * ↑↑k.snd
K : κ → Subgroup G := fun k ↦ if (H ↑k.fst).FiniteIndex then D else H ↑k.fst
⊢ (⋃ x ∈ {k | (H ↑k.fst).FiniteIndex}, f x • ↑(K x)) ∪ ⋃ x ∈ {a | ¬(H ↑a.fst).FiniteIndex}, f x • ↑(K x) =
    (⋃ x ∈ {i ∈ s | (H i).FiniteIndex}, g x • ↑(H x)) ∪ ⋃ x ∈ {a ∈ s | ¬(H a).FiniteIndex}, g x • ↑(H x)

Tactic:
apply congrArg₂ (· ∪ ·) <;> rw [Set.iUnion_sigma, Set.iUnion_subtype] <;>
        refine Set.iUnion_congr fun i => ?_

Goal state after:
case hx
G : Type u_1
inst✝¹ : Group G
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
inst✝ : DecidablePred FiniteIndex
hcovers : ⋃ i ∈ {i ∈ s | (H i).FiniteIndex} ∪ {a ∈ s | ¬(H a).FiniteIndex}, g i • ↑(H i) = Set.univ
D : Subgroup G := ⨅ k ∈ {i ∈ s | (H i).FiniteIndex}, H k
hD : D.FiniteIndex
hD_le : ∀ {i : ι}, i ∈ s → (H i).FiniteIndex → D ≤ H i
t : (i : ι) → i ∈ s → (H i).FiniteIndex → Finset ↥(H i)
ht :
  ∀ (i : ι) (hi : i ∈ s) (hfi : (H i).FiniteIndex),
    IsComplement ↑(t i hi hfi) ↑(D.subgroupOf (H i)) ∧ ⋃ g ∈ t i hi hfi, ↑g • ↑D = ↑(H i)
κ : Type (max u_2 u_1) := (i : ↥s) × ↥(if h : (H ↑i).FiniteIndex then t ↑i ⋯ h else {1})
f : κ → G := fun k ↦ g ↑k.fst * ↑↑k.snd
K : κ → Subgroup G := fun k ↦ if (H ↑k.fst).FiniteIndex then D else H ↑k.fst
i : ι
⊢ ⋃ (hx : i ∈ s), ⋃ a, ⋃ (_ : ⟨⟨i, hx⟩, a⟩ ∈ {k | (H ↑k.fst).FiniteIndex}), f ⟨⟨i, hx⟩, a⟩ • ↑(K ⟨⟨i, hx⟩, a⟩) =
    ⋃ (_ : i ∈ {i ∈ s | (H i).FiniteIndex}), g i • ↑(H i)

case hy
G : Type u_1
inst✝¹ : Group G
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
inst✝ : DecidablePred FiniteIndex
hcovers : ⋃ i ∈ {i ∈ s | (H i).FiniteIndex} ∪ {a ∈ s | ¬(H a).FiniteIndex}, g i • ↑(H i) = Set.univ
D : Subgroup G := ⨅ k ∈ {i ∈ s | (H i).FiniteIndex}, H k
hD : D.FiniteIndex
hD_le : ∀ {i : ι}, i ∈ s → (H i).FiniteIndex → D ≤ H i
t : (i : ι) → i ∈ s → (H i).FiniteIndex → Finset ↥(H i)
ht :
  ∀ (i : ι) (hi : i ∈ s) (hfi : (H i).FiniteIndex),
    IsComplement ↑(t i hi hfi) ↑(D.subgroupOf (H i)) ∧ ⋃ g ∈ t i hi hfi, ↑g • ↑D = ↑(H i)
κ : Type (max u_2 u_1) := (i : ↥s) × ↥(if h : (H ↑i).FiniteIndex then t ↑i ⋯ h else {1})
f : κ → G := fun k ↦ g ↑k.fst * ↑↑k.snd
K : κ → Subgroup G := fun k ↦ if (H ↑k.fst).FiniteIndex then D else H ↑k.fst
i : ι
⊢ ⋃ (hx : i ∈ s), ⋃ a, ⋃ (_ : ⟨⟨i, hx⟩, a⟩ ∈ {a | ¬(H ↑a.fst).FiniteIndex}), f ⟨⟨i, hx⟩, a⟩ • ↑(K ⟨⟨i, hx⟩, a⟩) =
    ⋃ (_ : i ∈ {a ∈ s | ¬(H a).FiniteIndex}), g i • ↑(H i)
Module: Mathlib.FieldTheory.KummerExtension

Goal state before:
pp: case isFalse
K : Type u
inst✝¹ : Field K
n : ℕ
hζ : (primitiveRoots n K).Nonempty
a : K
H : Irreducible (X ^ n - C a)
inst✝ : NeZero n
σ : Gal(K[n√a]/K)
this✝¹ : Fact (Irreducible (X ^ n - C a)) := { out := H }
this✝ : IsDomain K[n√a] := inferInstance
this : DecidableEq K := Classical.decEq K
h✝ : ¬a = 0
⊢ σ (root (X ^ n - C a)) ^ n / root (X ^ n - C a) ^ n = 1

Tactic:
← map_pow

Goal state after:
case isFalse
K : Type u
inst✝¹ : Field K
n : ℕ
hζ : (primitiveRoots n K).Nonempty
a : K
H : Irreducible (X ^ n - C a)
inst✝ : NeZero n
σ : Gal(K[n√a]/K)
this✝¹ : Fact (Irreducible (X ^ n - C a)) := { out := H }
this✝ : IsDomain K[n√a] := inferInstance
this : DecidableEq K := Classical.decEq K
h✝ : ¬a = 0
⊢ σ (root (X ^ n - C a) ^ n) / root (X ^ n - C a) ^ n = 1
Module: Mathlib.GroupTheory.CosetCover

Goal state before:
pp: case inr
G : Type u_1
inst✝ : Group G
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
hcovers : ⋃ i ∈ s, g i • ↑(H i) = Set.univ
h : ∀ i ∈ s, (H i).FiniteIndex → s.card < (H i).index
hs : s.Nonempty
hs' : 0 < s.card
hlt : ∀ i ∈ s, (↑(H i).index)⁻¹ < (↑s.card)⁻¹
⊢ s.card • (↑s.card)⁻¹ = 1

Tactic:
nsmul_eq_mul,

Goal state after:
case inr
G : Type u_1
inst✝ : Group G
ι : Type u_2
H : ι → Subgroup G
g : ι → G
s : Finset ι
hcovers : ⋃ i ∈ s, g i • ↑(H i) = Set.univ
h : ∀ i ∈ s, (H i).FiniteIndex → s.card < (H i).index
hs : s.Nonempty
hs' : 0 < s.card
hlt : ∀ i ∈ s, (↑(H i).index)⁻¹ < (↑s.card)⁻¹
⊢ ↑s.card * (↑s.card)⁻¹ = 1
Module: Mathlib.RingTheory.LinearDisjoint

Goal state before:
pp: R : Type u
S : Type v
inst✝³ : CommRing R
inst✝² : Ring S
inst✝¹ : Algebra R S
A B : Subalgebra R S
H : A.LinearDisjoint B
inst✝ : Flat R ↥A
ι : Type u_1
b : ι → ↥B
hb : LinearIndependent R b
h : ((toSubmodule A).mulRightMap b).ker = ⊥
⊢ LinearIndependent (↥A) (⇑B.val ∘ b)

Tactic:
rwa [mulRightMap_ker_eq_bot_iff_linearIndependent] at h

Goal state after:
Module: Mathlib.FieldTheory.NormalizedTrace

Goal state before:
pp: F : Type u_1
K : Type u_2
inst✝⁴ : Field F
inst✝³ : Field K
inst✝² : Algebra F K
inst✝¹ : CharZero F
inst✝ : FiniteDimensional F K
a : K
h : ↑(Module.finrank (↥F⟮a⟯) K) ≠ 0
⊢ normalizedTraceAux F K a =
    Module.finrank (↥F⟮a⟯) K • (trace F ↥F⟮a⟯) (AdjoinSimple.gen F a) /
      ↑(Module.finrank F ↥F⟮a⟯ * Module.finrank (↥F⟮a⟯) K)

Tactic:
nsmul_eq_mul,

Goal state after:
F : Type u_1
K : Type u_2
inst✝⁴ : Field F
inst✝³ : Field K
inst✝² : Algebra F K
inst✝¹ : CharZero F
inst✝ : FiniteDimensional F K
a : K
h : ↑(Module.finrank (↥F⟮a⟯) K) ≠ 0
⊢ normalizedTraceAux F K a =
    ↑(Module.finrank (↥F⟮a⟯) K) * (trace F ↥F⟮a⟯) (AdjoinSimple.gen F a) /
      ↑(Module.finrank F ↥F⟮a⟯ * Module.finrank (↥F⟮a⟯) K)
Module: Mathlib.RingTheory.LinearDisjoint

Goal state before:
pp: R : Type u
S : Type v
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
A : Type v
inst✝³ : Ring A
B : Type w
inst✝² : Ring B
inst✝¹ : Algebra R A
inst✝ : Algebra R B
H : IsField (A ⊗[R] B)
fa : A →ₐ[R] S
fb : B →ₐ[R] S
hfa : Function.Injective ⇑fa
hfb : Function.Injective ⇑fb
⊢ fa.range.LinearDisjoint fb.range

Tactic:
apply of_isField
  exact Algebra.TensorProduct.congr (AlgEquiv.ofInjective fa hfa)
    (AlgEquiv.ofInjective fb hfb) |>.symm.toMulEquiv.isField H

Goal state after:
Module: Mathlib.FieldTheory.LinearDisjoint

Goal state before:
pp: F : Type u
E : Type v
inst✝⁶ : Field F
inst✝⁵ : Field E
inst✝⁴ : Algebra F E
A : IntermediateField F E
L : Type w
inst✝³ : Field L
inst✝² : Algebra F L
inst✝¹ : Algebra L E
inst✝ : IsScalarTower F L E
H : A.LinearDisjoint L
halg : Algebra.IsAlgebraic F ↥A ∨ Algebra.IsAlgebraic F L
L' : Subalgebra F E := (IsScalarTower.toAlgHom F L E).range
⊢ Module.rank ↥A ↥(extendScalars ⋯) = Module.rank ↥A.toSubalgebra ↥(Algebra.adjoin ↥A.toSubalgebra ↑L')

Tactic:
have heq : (adjoin L (A : Set E)).toSubalgebra.toSubsemiring =
      (Algebra.adjoin A (L' : Set E)).toSubsemiring := by
    rw [adjoin_intermediateField_toSubalgebra_of_isAlgebraic _ _ halg.symm,
      Algebra.adjoin_toSubsemiring, Algebra.adjoin_toSubsemiring, Set.union_comm]
    congr 2
    ext x
    simp

Goal state after:
F : Type u
E : Type v
inst✝⁶ : Field F
inst✝⁵ : Field E
inst✝⁴ : Algebra F E
A : IntermediateField F E
L : Type w
inst✝³ : Field L
inst✝² : Algebra F L
inst✝¹ : Algebra L E
inst✝ : IsScalarTower F L E
H : A.LinearDisjoint L
halg : Algebra.IsAlgebraic F ↥A ∨ Algebra.IsAlgebraic F L
L' : Subalgebra F E := (IsScalarTower.toAlgHom F L E).range
heq : (adjoin L ↑A).toSubsemiring = (Algebra.adjoin ↥A ↑L').toSubsemiring
⊢ Module.rank ↥A ↥(extendScalars ⋯) = Module.rank ↥A.toSubalgebra ↥(Algebra.adjoin ↥A.toSubalgebra ↑L')
Module: Mathlib.RingTheory.LinearDisjoint

Goal state before:
pp: R : Type u
S : Type v
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
A B : Subalgebra R S
H : A.LinearDisjoint B
inst✝³ : Free R ↥A
inst✝² : Flat R ↥B
inst✝¹ : Nontrivial R
inst✝ : Nontrivial S
⊢ Module.rank ↥B ↥(Submodule.span (↥B) (Set.range fun i ↦ ↑((Free.chooseBasis R ↥A) i))) =
    Cardinal.mk (Free.ChooseBasisIndex R ↥A)

Tactic:
change Module.rank B (Submodule.span B (Set.range (A.val ∘ Module.Free.chooseBasis R A))) = _

Goal state after:
R : Type u
S : Type v
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
A B : Subalgebra R S
H : A.LinearDisjoint B
inst✝³ : Free R ↥A
inst✝² : Flat R ↥B
inst✝¹ : Nontrivial R
inst✝ : Nontrivial S
⊢ Module.rank ↥B ↥(Submodule.span (↥B) (Set.range (⇑A.val ∘ ⇑(Free.chooseBasis R ↥A)))) =
    Cardinal.mk (Free.ChooseBasisIndex R ↥A)
Module: Mathlib.FieldTheory.RatFunc.Valuation

Goal state before:
pp: F : Type u_1
inst✝¹ : Field F
inst✝ : DecidableEq F⟮X⟯
p : F[X]
hp : p ≠ 0
⊢ exp ((algebraMap F[X] F⟮X⟯) p).intDegree = exp ↑p.natDegree

Tactic:
RatFunc.intDegree_polynomial

Goal state after:
F : Type u_1
inst✝¹ : Field F
inst✝ : DecidableEq F⟮X⟯
p : F[X]
hp : p ≠ 0
⊢ exp ↑p.natDegree = exp ↑p.natDegree
Module: Mathlib.FieldTheory.RatFunc.Luroth

Goal state before:
pp: K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
⊢ Polynomial.map (algebraMap K[X] K⟮X⟯) (Q₁ h * Φ E) = Polynomial.map (algebraMap K[X] K⟮X⟯) (θ E)

Tactic:
rw [Polynomial.map_mul, map_Q₁, Q₀_mul_Φ h]

Goal state after:
Module: Mathlib.FieldTheory.RatFunc.Luroth

Goal state before:
pp: K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
this : (Polynomial.map Polynomial.C (Q₂ h) * Φ E).natDegree = (θ E).natDegree
⊢ (Φ E).natDegree = (θ E).natDegree

Tactic:
natDegree_mul (Polynomial.map_ne_zero (Q₂_ne_zero h)) (Φ_ne_zero h),

Goal state after:
K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
this : (Polynomial.map Polynomial.C (Q₂ h)).natDegree + (Φ E).natDegree = (θ E).natDegree
⊢ (Φ E).natDegree = (θ E).natDegree
Module: Mathlib.Geometry.Euclidean.Projection

Goal state before:
pp: 𝕜 : Type u_1
V : Type u_2
P : Type u_3
inst✝⁶ : RCLike 𝕜
inst✝⁵ : NormedAddCommGroup V
inst✝⁴ : InnerProductSpace 𝕜 V
inst✝³ : MetricSpace P
inst✝² : NormedAddTorsor V P
s : AffineSubspace 𝕜 P
inst✝¹ : Nonempty ↥s
inst✝ : s.direction.HasOrthogonalProjection
p : P
⊢ ↑s ∩ ↑(mk' p s.directionᗮ) = {↑((orthogonalProjection s) p)}

Tactic:
by
  obtain ⟨q, hq⟩ := inter_eq_singleton_of_nonempty_of_isCompl (nonempty_subtype.mp ‹_›)
    (mk'_nonempty p s.directionᗮ)
    (by
      rw [direction_mk' p s.directionᗮ]
      exact s.direction.isCompl_orthogonal)
  rwa [Set.eq_singleton_iff_nonempty_unique_mem.1 hq |>.2 _
    ⟨orthogonalProjection_mem _, orthogonalProjection_mem_orthogonal _ _⟩]

Goal state after:
Module: Mathlib.Geometry.Euclidean.Projection

Goal state before:
pp: case mpr
𝕜 : Type u_1
V : Type u_2
P : Type u_3
inst✝⁶ : RCLike 𝕜
inst✝⁵ : NormedAddCommGroup V
inst✝⁴ : InnerProductSpace 𝕜 V
inst✝³ : MetricSpace P
inst✝² : NormedAddTorsor V P
s : AffineSubspace 𝕜 P
inst✝¹ : Nonempty ↥s
inst✝ : s.direction.HasOrthogonalProjection
p q : P
hqs : q ∈ s
hpq : p -ᵥ q ∈ s.directionᗮ
hq : q ∈ mk' p s.directionᗮ
⊢ ↑((orthogonalProjection s) p) = q

Tactic:
suffices q ∈ ({(orthogonalProjection s p : P)} : Set P) by
      simpa [eq_comm] using this

Goal state after:
case mpr
𝕜 : Type u_1
V : Type u_2
P : Type u_3
inst✝⁶ : RCLike 𝕜
inst✝⁵ : NormedAddCommGroup V
inst✝⁴ : InnerProductSpace 𝕜 V
inst✝³ : MetricSpace P
inst✝² : NormedAddTorsor V P
s : AffineSubspace 𝕜 P
inst✝¹ : Nonempty ↥s
inst✝ : s.direction.HasOrthogonalProjection
p q : P
hqs : q ∈ s
hpq : p -ᵥ q ∈ s.directionᗮ
hq : q ∈ mk' p s.directionᗮ
⊢ q ∈ {↑((orthogonalProjection s) p)}
Module: Mathlib.Geometry.Euclidean.Projection

Goal state before:
pp: 𝕜 : Type u_1
V : Type u_2
P : Type u_3
inst✝⁶ : RCLike 𝕜
inst✝⁵ : NormedAddCommGroup V
inst✝⁴ : InnerProductSpace 𝕜 V
inst✝³ : MetricSpace P
inst✝² : NormedAddTorsor V P
s : AffineSubspace 𝕜 P
inst✝¹ : Nonempty ↥s
inst✝ : s.direction.HasOrthogonalProjection
p : P
hp : p ∈ s
v : V
hv : v ∈ s.directionᗮ
⊢ ↑⟨p, hp⟩ ∈ s ∧ (v +ᵥ p) -ᵥ ↑⟨p, hp⟩ ∈ s.directionᗮ

Tactic:
simp [*]

Goal state after:
Module: Mathlib.Geometry.Euclidean.Projection

Goal state before:
pp: 𝕜 : Type u_1
V : Type u_2
P : Type u_3
inst✝⁸ : RCLike 𝕜
inst✝⁷ : NormedAddCommGroup V
inst✝⁶ : InnerProductSpace 𝕜 V
inst✝⁵ : MetricSpace P
inst✝⁴ : NormedAddTorsor V P
s : AffineSubspace 𝕜 P
inst✝³ : Nonempty ↥s
s' : AffineSubspace 𝕜 ↥s
inst✝² : Nonempty ↥s'
inst✝¹ : s'.direction.HasOrthogonalProjection
inst✝ : (map s.subtype s').direction.HasOrthogonalProjection
p : ↥s
⊢ ↑↑((orthogonalProjection s') p) = ↑((orthogonalProjection (map s.subtype s')) ↑p)

Tactic:
rw [eq_comm]
  have : (s'.map s.subtypeₐᵢ.toAffineMap).direction.HasOrthogonalProjection := by
    rw [subtypeₐᵢ_toAffineMap]
    infer_instance
  convert! orthogonalProjection_map s' s.subtypeₐᵢ p

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Affine

Goal state before:
pp: case funProp.discharger
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
x : P × P × P
hx12 : x.1 ≠ x.2.1
hx32 : x.2.2 ≠ x.2.1
⊢ (x.1 -ᵥ x.2.1, x.2.2 -ᵥ x.2.1).1 ≠ 0

Tactic:
simp [*]

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Affine

Goal state before:
pp: case funProp.discharger
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
x : P × P × P
hx12 : x.1 ≠ x.2.1
hx32 : x.2.2 ≠ x.2.1
⊢ (x.1 -ᵥ x.2.1, x.2.2 -ᵥ x.2.1).2 ≠ 0

Tactic:
simp [*]

Goal state after: