mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Combinatorics.Matroid.Map

Goal state before:
pp: α : Type u_1
β : Type u_2
M : Matroid α
I X : Set α
f : α → β
hf : InjOn f M.E
hI : I ⊆ M.E
hX : X ⊆ M.E
h : (M.map f hf).IsBasis (f '' I) (f '' X)
hI' : M.Indep I
hss : I ⊆ X
J : Set α
hJ : M.Indep J
hIJ : I ⊆ J
hJX : J ⊆ X
hIJ' : f '' I = f '' J
⊢ J ⊆ I

Tactic:
hf.image_eq_image_iff hI hJ.subset_ground

Goal state after:
α : Type u_1
β : Type u_2
M : Matroid α
I X : Set α
f : α → β
hf : InjOn f M.E
hI : I ⊆ M.E
hX : X ⊆ M.E
h : (M.map f hf).IsBasis (f '' I) (f '' X)
hI' : M.Indep I
hss : I ⊆ X
J : Set α
hJ : M.Indep J
hIJ : I ⊆ J
hJX : J ⊆ X
hIJ' : I = J
⊢ J ⊆ I
Module: Mathlib.Combinatorics.Matroid.Map

Goal state before:
pp: α : Type u_1
M : Matroid α
⊢ (M ↾ M.E)✶.comapOn (M.E ↓∩ (M ↾ M.E).E) Subtype.val = M✶.restrictSubtype M.E

pp: α : Type u_1
M : Matroid α
⊢ BijOn Subtype.val (M.E ↓∩ (M ↾ M.E).E) (M ↾ M.E).E

Tactic:
restrict_ground_eq_self,

Goal state after:
α : Type u_1
M : Matroid α
⊢ M✶.comapOn (M.E ↓∩ M.E) Subtype.val = M✶.restrictSubtype M.E

α : Type u_1
M : Matroid α
⊢ BijOn Subtype.val (M.E ↓∩ (M ↾ M.E).E) (M ↾ M.E).E
Module: Mathlib.Combinatorics.Matroid.Loop

Goal state before:
pp: α : Type u_1
M : Matroid α
E : Set α
h : M = loopyOn E
⊢ M.loops = E ∧ M.E = E

Tactic:
simp [h, loops]

Goal state after:
Module: Mathlib.Combinatorics.Matroid.Rank.ENat

Goal state before:
pp: α : Type u_1
M : Matroid α
R X I : Set α
hI : (M ↾ R).IsBasis' I X
⊢ I.encard = M.eRk (X ∩ R)

Tactic:
rw [isBasis'_iff_isBasis_inter_ground, isBasis_restrict_iff', restrict_ground_eq] at hI

Goal state after:
α : Type u_1
M : Matroid α
R X I : Set α
hI : M.IsBasis I (X ∩ R ∩ M.E) ∧ X ∩ R ⊆ R
⊢ I.encard = M.eRk (X ∩ R)
Module: Mathlib.Combinatorics.Matroid.Loop

Goal state before:
pp: case inr
α : Type u_1
M : Matroid α
e f : α
he : M.IsNonloop e
hf : M.IsNonloop f
hne : e ≠ f
⊢ ¬M.Indep {e, f} → ∀ e_1 ∈ {e, f}, M.Indep ({e, f} \ {e_1})

Tactic:
rintro hi x (rfl | rfl)

Goal state after:
case inr.inl
α : Type u_1
M : Matroid α
f : α
hf : M.IsNonloop f
x : α
he : M.IsNonloop x
hne : x ≠ f
hi : ¬M.Indep {x, f}
⊢ M.Indep ({x, f} \ {x})

case inr.inr
α : Type u_1
M : Matroid α
e : α
he : M.IsNonloop e
x : α
hf : M.IsNonloop x
hne : e ≠ x
hi : ¬M.Indep {e, x}
⊢ M.Indep ({e, x} \ {x})
Module: Mathlib.Combinatorics.Matroid.Rank.ENat

Goal state before:
pp: α : Type u_1
M : Matroid α
I : Set α
hX : M.IsRkFinite I
h : I.encard ≤ M.eRk I
⊢ M.Indep I

Tactic:
by
  rw [indep_iff_eRk_eq_encard_of_finite _]
  · exact (M.eRk_le_encard I).antisymm h
  simpa using h.trans_lt hX.eRk_lt_top

Goal state after:
Module: Mathlib.Combinatorics.Matroid.Rank.ENat

Goal state before:
pp: α : Type u_1
X : Set α
β : Type u_2
f : α → β
M : Matroid α
hf : InjOn f M.E
hX : X ⊆ M.E
I : Set α
hI : M.IsBasis I X
⊢ (M.map f hf).eRk (f '' X) = M.eRk X

Tactic:
rw [hI.eRk_eq_encard, (hI.map hf).eRk_eq_encard, (hf.mono hI.indep.subset_ground).encard_image]

Goal state after:
Module: Mathlib.Combinatorics.Matroid.Circuit

Goal state before:
pp: α : Type u_1
M : Matroid α
⊢ M✶.RankPos ↔ ∃ C, M.IsCircuit C

Tactic:
rw [rankPos_iff, dual_isBase_iff, sdiff_empty, not_iff_comm, not_exists,
    ← ground_indep_iff_isBase, indep_iff_forall_subset_not_isCircuit]

Goal state after:
α : Type u_1
M : Matroid α
⊢ (∀ (x : Set α), ¬M.IsCircuit x) ↔ ∀ C ⊆ M.E, ¬M.IsCircuit C
Module: Mathlib.Combinatorics.Matroid.Rank.Cardinal

Goal state before:
pp: case refine_1
α : Type u
M : Matroid α
h : M.RankFinite
⊢ M.cRank < ℵ₀

Tactic:
have ⟨B, hB, fin⟩ := h

Goal state after:
case refine_1
α : Type u
M : Matroid α
h : M.RankFinite
B : Set α
hB : M.IsBase B
fin : B.Finite
⊢ M.cRank < ℵ₀
Module: Mathlib.RingTheory.AlgebraicIndependent.Transcendental

Goal state before:
pp: ι : Type u_1
R : Type u_3
A : Type v
x : ι → A
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : Unique ι
i : MvPolynomial ι R ≃ₐ[R] Polynomial R := uniqueAlgEquiv R ι
⊢ aeval x = (Polynomial.aeval (x default)).comp ↑i

Tactic:
ext y

Goal state after:
ι : Type u_1
R : Type u_3
A : Type v
x : ι → A
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : Unique ι
i : MvPolynomial ι R ≃ₐ[R] Polynomial R := uniqueAlgEquiv R ι
y : ι
⊢ (aeval x) (X y) = ((Polynomial.aeval (x default)).comp ↑i) (X y)
Module: Mathlib.Combinatorics.Matroid.Closure

Goal state before:
pp: α : Type u_2
M : Matroid α
S T : Set α
hS : M.Spanning S
hST : S ⊆ T
hT : T ⊆ M.E
⊢ M.E ⊆ M.closure T

Tactic:
by rw [← hS.closure_eq]; exact M.closure_subset_closure hST

Goal state after:
Module: Mathlib.GroupTheory.GroupAction.FixedPoints

Goal state before:
pp: α : Type u_1
M : Type u_3
inst✝² : Monoid M
inst✝¹ : MulAction M α
inst✝ : FaithfulSMul M α
m : M
⊢ (∀ (x : α), x ∈ fixedBy α m) ↔ (fun x2 ↦ m • x2) = fun x2 ↦ 1 • x2

Tactic:
simp_rw [funext_iff, one_smul, mem_fixedBy]

Goal state after:
Module: Mathlib.RingTheory.AlgebraicIndependent.TranscendenceBasis

Goal state before:
pp: ι : Type u
R : Type u_1
S : Type v
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FaithfulSMul R S
inst✝ : NoZeroDivisors S
s : Set ι
i j : ι
v : ι → S
hj : j ∈ insert i s
H₁ : IsTranscendenceBasis R fun x ↦ v ↑x
this✝² : Nontrivial ↥(adjoin R (v '' (insert i s \ {j})))
this✝¹ : Nontrivial S
this✝ : IsDomain S
H₂ : v j ∈ (matroid R S).closure (v '' (insert i s \ {j}))
this : Nontrivial R
inj : InjOn v s
⊢ IsTranscendenceBasis R fun x ↦ v ↑x

Tactic:
have H' := image_eq_range .. ▸ matroid_isBase_iff.mpr H₁.to_subtype_range

Goal state after:
ι : Type u
R : Type u_1
S : Type v
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FaithfulSMul R S
inst✝ : NoZeroDivisors S
s : Set ι
i j : ι
v : ι → S
hj : j ∈ insert i s
H₁ : IsTranscendenceBasis R fun x ↦ v ↑x
this✝² : Nontrivial ↥(adjoin R (v '' (insert i s \ {j})))
this✝¹ : Nontrivial S
this✝ : IsDomain S
H₂ : v j ∈ (matroid R S).closure (v '' (insert i s \ {j}))
this : Nontrivial R
inj : InjOn v s
H' : (matroid R S).IsBase (v '' s)
⊢ IsTranscendenceBasis R fun x ↦ v ↑x
Module: Mathlib.RingTheory.AlgebraicIndependent.TranscendenceBasis

Goal state before:
pp: ι : Type u
R : Type u_1
S : Type v
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FaithfulSMul R S
inst✝ : NoZeroDivisors S
s : Set ι
i j : ι
v : ι → S
hj✝ : j ∈ insert i s
H₁ : IsTranscendenceBasis R fun x ↦ v ↑x
this✝² : Nontrivial ↥(adjoin R (v '' (insert i s \ {j})))
this✝¹ : Nontrivial S
this✝ : IsDomain S
H₂ : v j ∈ (matroid R S).closure (v '' (insert i s \ {j}))
this : Nontrivial R
inj : InjOn v s
H' : (matroid R S).IsBase (v '' s)
hj : j ∈ s
Hj : v j ∉ (matroid R S).closure (v '' s \ {v j})
hi : i ∉ s
ne : v i ≠ v j
his : v i ∈ v '' s
⊢ v j ∈ (matroid R S).closure (v '' s \ {v j})

Tactic:
by
    refine Matroid.closure_subset_closure _ ?_ H₂
    rintro x ⟨k, ⟨rfl | hks, hkj⟩, rfl⟩
    · exact ⟨his, ne⟩
    · exact ⟨⟨k, hks, rfl⟩, inj.ne hks hj hkj⟩

Goal state after:
Module: Mathlib.FieldTheory.SeparableClosure

Goal state before:
pp: F : Type u
E : Type v
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
p : F[X]
sp : IsSplittingField F E p
hp : p.Separable
⊢ ∀ x ∈ p.rootSet E, IsSeparable F x

Tactic:
exact fun x hx ↦ hp.of_dvd (minpoly.dvd F x (aeval_eq_zero_of_mem_rootSet hx))

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

Goal state before:
pp: R : Type u_1
M : Type u_2
inst✝⁴ : Ring R
inst✝³ : TopologicalSpace R
inst✝² : AddCommGroup M
inst✝¹ : Module R M
B : ModuleFilterBasis R M
inst✝ : IsTopologicalRing R
⊢ ContinuousSMul R M

Tactic:
let B' := B.toAddGroupFilterBasis
  let _ := B'.topology
  exact ContinuousSMul.of_basis_zero B'.nhds_zero_hasBasis
      (fun {_} => by simpa using! B.smul)
      (by simpa using! B.smul_left) B.smul_right

Goal state after:
Module: Mathlib.FieldTheory.SeparableDegree

Goal state before:
pp: F : Type u
E : Type v
inst✝³ : Field F
inst✝² : Field E
inst✝¹ : Algebra F E
inst✝ : Algebra.IsSeparable F E
⊢ finSepDegree F E = finrank F E

Tactic:
wlog hfd : FiniteDimensional F E generalizing E with H
  · rw [finrank_of_infinite_dimensional hfd]
    obtain ⟨L, h, h'⟩ := exists_lt_finrank_of_infinite_dimensional hfd (finSepDegree F E)
    have hd := finSepDegree_mul_finSepDegree_of_isAlgebraic F L E
    rw [H L h] at hd
    by_cases hd' : finSepDegree L E = 0
    · rw [← hd, hd', mul_zero]
    linarith only [h', hd, Nat.le_mul_of_pos_right (finrank F L) (Nat.pos_of_ne_zero hd')]
  rw [← finSepDegree_top F, ← finrank_top F E]
  refine induction_on_adjoin (fun K : IntermediateField F E ↦ finSepDegree F K = finrank F K)
    (by simp_rw [finSepDegree_bot, IntermediateField.finrank_bot]) (fun L x h ↦ ?_) ⊤
  have heq : _ * _ = _ * _ := congr_arg₂ (· * ·) h <|
    (finSepDegree_adjoin_simple_eq_finrank_iff L E x (IsAlgebraic.of_finite L x)).2 <|
      IsSeparable.tower_top L (Algebra.IsSeparable.isSeparable F x)
  set M := L⟮x⟯
  rwa [finSepDegree_mul_finSepDegree_of_isAlgebraic F L M,
    Module.finrank_mul_finrank F L M] at heq

Goal state after:
Module: Mathlib.FieldTheory.KrullTopology

Goal state before:
pp: K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Algebra.IsIntegral K L
⊢ Pairwise fun x1 x2 ↦ ∃ U, IsClopen U ∧ x1 ∈ U ∧ x2 ∈ Uᶜ

Tactic:
intro σ τ h_diff

Goal state after:
K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Algebra.IsIntegral K L
σ τ : Gal(L/K)
h_diff : σ ≠ τ
⊢ ∃ U, IsClopen U ∧ σ ∈ U ∧ τ ∈ Uᶜ
Module: Mathlib.FieldTheory.KrullTopology

Goal state before:
pp: K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Algebra.IsIntegral K L
x : L
E : IntermediateField K L := K⟮x⟯
⊢ IsOpen ↑(MulAction.stabilizer Gal(L/K) x)

Tactic:
have hL : FiniteDimensional K E := adjoin.finiteDimensional (Algebra.IsIntegral.isIntegral x)

Goal state after:
K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Algebra.IsIntegral K L
x : L
E : IntermediateField K L := K⟮x⟯
hL : FiniteDimensional K ↥E
⊢ IsOpen ↑(MulAction.stabilizer Gal(L/K) x)
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: F : Type u_1
E : Type u_2
inst✝³ : Field F
inst✝² : Field E
inst✝¹ : Algebra F E
K L : IntermediateField F E
inst✝ : Normal F ↥K
h✝ : K ⊔ L = ⊤
φ : Gal(E/↥L)
hφ : (restrictRestrictAlgEquivMapHom F (↥K) (↥L) E) φ = 1
h : (MulSemiringAction.toAlgAut Gal(E/↥L) F E) φ = 1
⊢ φ = 1

Tactic:
rwa [AlgEquiv.ext_iff] at h ⊢

Goal state after:
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: F : Type u_1
E : Type u_2
E' : Type u_3
inst✝⁷ : Field F
inst✝⁶ : Field E
inst✝⁵ : Field E'
inst✝⁴ : Algebra F E
inst✝³ : Algebra F E'
inst✝² : Algebra E E'
inst✝¹ : IsScalarTower F E E'
L : IntermediateField F E
inst✝ : Normal F E
⊢ (map (IsScalarTower.toAlgHom F E E') L).fixingSubgroup = Subgroup.comap (restrictNormalHom E) L.fixingSubgroup

Tactic:
ext f

Goal state after:
F : Type u_1
E : Type u_2
E' : Type u_3
inst✝⁷ : Field F
inst✝⁶ : Field E
inst✝⁵ : Field E'
inst✝⁴ : Algebra F E
inst✝³ : Algebra F E'
inst✝² : Algebra E E'
inst✝¹ : IsScalarTower F E E'
L : IntermediateField F E
inst✝ : Normal F E
f : Gal(E'/F)
⊢ f ∈ (map (IsScalarTower.toAlgHom F E E') L).fixingSubgroup ↔ f ∈ Subgroup.comap (restrictNormalHom E) L.fixingSubgroup
Module: Mathlib.RingTheory.Polynomial.GaussLemma

Goal state before:
pp: case refine_1
R : Type u_1
inst✝² : CommRing R
K : Type u_2
inst✝¹ : Field K
inst✝ : Algebra R K
f : R[X]
hf : f.Monic
g : K[X]
hg : g.Monic
hd : g ∣ map (algebraMap R K) f
a : g.SplittingField
ha : a ∈ (map (algebraMap K g.SplittingField) g).roots
⊢ a ∈ f.aroots g.SplittingField

Tactic:
rw [aroots_def, IsScalarTower.algebraMap_eq R K _, ← map_map]

Goal state after:
case refine_1
R : Type u_1
inst✝² : CommRing R
K : Type u_2
inst✝¹ : Field K
inst✝ : Algebra R K
f : R[X]
hf : f.Monic
g : K[X]
hg : g.Monic
hd : g ∣ map (algebraMap R K) f
a : g.SplittingField
ha : a ∈ (map (algebraMap K g.SplittingField) g).roots
⊢ a ∈ (map (algebraMap K g.SplittingField) (map (algebraMap R K) f)).roots
Module: Mathlib.FieldTheory.Galois.Infinite

Goal state before:
pp: case h.left
k : Type u_1
K : Type u_2
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
L : IntermediateField k K
inst✝ : IsGalois k K
σ : Gal(K/k)
h : σ ∈ (↑L.fixingSubgroup)ᶜ
y : K
yL : y ∈ ↑L
ne : y ∉ fun a ↦ σ • a = a
⊢ σ • ↑(adjoin k {y}).fixingSubgroup ⊆ (↑L.fixingSubgroup)ᶜ

Tactic:
intro f hf
      rcases (Set.mem_smul_set.mp hf) with ⟨g, hg, eq⟩
      simp only [Set.mem_compl_iff, SetLike.mem_coe, ← eq]
      apply (mem_fixingSubgroup_iff Gal(K/k)).not.mpr
      push Not
      use y
      simp only [yL, smul_eq_mul, AlgEquiv.smul_def, AlgEquiv.mul_apply, ne_eq, true_and]
      have : g y = y := (mem_fixingSubgroup_iff Gal(K/k)).mp hg y <|
        adjoin_simple_le_iff.mp le_rfl
      simpa only [this, ne_eq, AlgEquiv.smul_def] using! ne

Goal state after:
Module: Mathlib.FieldTheory.Minpoly.IsIntegrallyClosed

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : IsDomain R
inst✝⁷ : Algebra R S
K : Type u_3
inst✝⁶ : Field K
inst✝⁵ : Algebra R K
inst✝⁴ : IsFractionRing R K
inst✝³ : IsIntegrallyClosed R
inst✝² : IsDomain S
inst✝¹ : Algebra K S
inst✝ : IsScalarTower R K S
s : S
hs : IsIntegral R s
L : Type u_2 := FractionRing S
⊢ minpoly K s = map (algebraMap R K) (minpoly R s)

Tactic:
← isIntegrallyClosed_eq_field_fractions K L hs,

Goal state after:
R : Type u_1
S : Type u_2
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : IsDomain R
inst✝⁷ : Algebra R S
K : Type u_3
inst✝⁶ : Field K
inst✝⁵ : Algebra R K
inst✝⁴ : IsFractionRing R K
inst✝³ : IsIntegrallyClosed R
inst✝² : IsDomain S
inst✝¹ : Algebra K S
inst✝ : IsScalarTower R K S
s : S
hs : IsIntegral R s
L : Type u_2 := FractionRing S
⊢ minpoly K s = minpoly K ((algebraMap S L) s)
Module: Mathlib.FieldTheory.Minpoly.MinpolyDiv

Goal state before:
pp: R : Type u_2
S : Type u_1
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
x : S
hx : IsIntegral R x
inst✝ : Nontrivial S
⊢ (minpolyDiv R x).natDegree < (minpoly R x).natDegree

Tactic:
rw [← natDegree_minpolyDiv_succ hx]

Goal state after:
R : Type u_2
S : Type u_1
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
x : S
hx : IsIntegral R x
inst✝ : Nontrivial S
⊢ (minpolyDiv R x).natDegree < (minpolyDiv R x).natDegree + 1
Module: Mathlib.FieldTheory.Minpoly.MinpolyDiv

Goal state before:
pp: case a.ind.refine_2
R : Type u_2
S : Type u_1
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
hx : IsIntegral R x
a✝ : Nontrivial S
i : ℕ
hi :
  ∀ m < i,
    m ∈ Set.Iio (minpoly R x).natDegree →
      m ∈ (fun x_1 ↦ x ^ x_1) ⁻¹' ↑(Submodule.span R (Set.range (minpolyDiv R x).coeff))
hi' : i ∈ Set.Iio (minpoly R x).natDegree
this : (minpolyDiv R x).coeff ((minpolyDiv R x).natDegree - i) ∈ Submodule.span R (Set.range (minpolyDiv R x).coeff)
⊢ i ≤ (minpolyDiv R x).natDegree

Tactic:
rwa [← natDegree_minpolyDiv_succ hx, Set.mem_Iio, Nat.lt_succ_iff] at hi'

Goal state after:
Module: Mathlib.FieldTheory.Minpoly.MinpolyDiv

Goal state before:
pp: case pos
R : Type u_2
S : Type u_1
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
a✝ : Nontrivial S
hx : IsIntegral R x
⊢ (minpolyDiv R x).natDegree = (minpoly R x).natDegree - 1

Tactic:
rw [← natDegree_minpolyDiv_succ hx]

Goal state after:
case pos
R : Type u_2
S : Type u_1
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
a✝ : Nontrivial S
hx : IsIntegral R x
⊢ (minpolyDiv R x).natDegree = (minpolyDiv R x).natDegree + 1 - 1
Module: Mathlib.RingTheory.Polynomial.GaussLemma

Goal state before:
pp: R : Type u_1
inst✝⁵ : CommRing R
K : Type u_2
inst✝⁴ : Field K
inst✝³ : Algebra R K
inst✝² : IsFractionRing R K
inst✝¹ : IsDomain R
inst✝ : IsGCDMonoid R
f : R[X]
hf : f.IsPrimitive
g : K[X]
this : NormalizedGCDMonoid R := ⋯.some
x✝ : g * map (algebraMap R K) f ∈ lifts (algebraMap R K)
k : R[X]
hk : map (algebraMap R K) k = g * map (algebraMap R K) f
g' : R[X] := integerNormalization R⁰ g
b : R
hb₁ : b ∈ R⁰
hb₂ : map (algebraMap R K) g' = b • g
g'_mul_f : (g' * f).content = (b • k).content
⊢ g ∈ lifts (algebraMap R K)

Tactic:
have h := Associated.of_eq g'_mul_f

Goal state after:
R : Type u_1
inst✝⁵ : CommRing R
K : Type u_2
inst✝⁴ : Field K
inst✝³ : Algebra R K
inst✝² : IsFractionRing R K
inst✝¹ : IsDomain R
inst✝ : IsGCDMonoid R
f : R[X]
hf : f.IsPrimitive
g : K[X]
this : NormalizedGCDMonoid R := ⋯.some
x✝ : g * map (algebraMap R K) f ∈ lifts (algebraMap R K)
k : R[X]
hk : map (algebraMap R K) k = g * map (algebraMap R K) f
g' : R[X] := integerNormalization R⁰ g
b : R
hb₁ : b ∈ R⁰
hb₂ : map (algebraMap R K) g' = b • g
g'_mul_f : (g' * f).content = (b • k).content
h : Associated (g' * f).content (b • k).content
⊢ g ∈ lifts (algebraMap R K)
Module: Mathlib.FieldTheory.PurelyInseparable.Basic

Goal state before:
pp: F : Type u
E : Type v
inst✝⁵ : Field F
inst✝⁴ : Field E
inst✝³ : Algebra F E
inst✝² : IsPurelyInseparable F E
L : Type u_2
inst✝¹ : CommRing L
inst✝ : IsReduced L
f g : E →+* L
heq : (fun f ↦ f.comp (algebraMap F E)) f = (fun f ↦ f.comp (algebraMap F E)) g
⊢ f = g

Tactic:
ext x
  let q := ringExpChar F
  obtain ⟨n, y, h⟩ := IsPurelyInseparable.pow_mem F q x
  replace heq := congr($heq y)
  simp_rw [RingHom.comp_apply, h, map_pow] at heq
  nontriviality L
  have := expChar_of_injective_ringHom (f.comp (algebraMap F E)).injective q
  exact iterateFrobenius_inj L q n heq

Goal state after:
Module: Mathlib.RingTheory.DedekindDomain.IntegralClosure

Goal state before:
pp: case refine_1
A : Type u_1
K : Type u_2
inst✝¹⁴ : CommRing A
inst✝¹³ : Field K
inst✝¹² : Algebra A K
inst✝¹¹ : IsFractionRing A K
L : Type u_3
inst✝¹⁰ : Field L
C : Type u_4
inst✝⁹ : CommRing C
inst✝⁸ : Algebra K L
inst✝⁷ : Algebra A L
inst✝⁶ : IsScalarTower A K L
inst✝⁵ : Algebra C L
inst✝⁴ : IsIntegralClosure C A L
inst✝³ : Algebra A C
inst✝² : IsScalarTower A C L
inst✝¹ : IsDomain A
inst✝ : Algebra.IsAlgebraic K L
this✝¹ : IsDomain C
this✝ : IsTorsionFree A L
this : IsTorsionFree A C
x : A
hx : x ∈ ↑A⁰
⊢ (algebraMap A C) x ≠ 0

Tactic:
map_ne_zero_iff _ (FaithfulSMul.algebraMap_injective A C)

Goal state after:
case refine_1
A : Type u_1
K : Type u_2
inst✝¹⁴ : CommRing A
inst✝¹³ : Field K
inst✝¹² : Algebra A K
inst✝¹¹ : IsFractionRing A K
L : Type u_3
inst✝¹⁰ : Field L
C : Type u_4
inst✝⁹ : CommRing C
inst✝⁸ : Algebra K L
inst✝⁷ : Algebra A L
inst✝⁶ : IsScalarTower A K L
inst✝⁵ : Algebra C L
inst✝⁴ : IsIntegralClosure C A L
inst✝³ : Algebra A C
inst✝² : IsScalarTower A C L
inst✝¹ : IsDomain A
inst✝ : Algebra.IsAlgebraic K L
this✝¹ : IsDomain C
this✝ : IsTorsionFree A L
this : IsTorsionFree A C
x : A
hx : x ∈ ↑A⁰
⊢ x ≠ 0
Module: Mathlib.RingTheory.DedekindDomain.IntegralClosure

Goal state before:
pp: A : Type u_1
K : Type u_2
inst✝¹⁷ : CommRing A
inst✝¹⁶ : Field K
inst✝¹⁵ : Algebra A K
inst✝¹⁴ : IsFractionRing A K
L : Type u_3
inst✝¹³ : Field L
C : Type u_4
inst✝¹² : CommRing C
inst✝¹¹ : Algebra K L
inst✝¹⁰ : Algebra A L
inst✝⁹ : IsScalarTower A K L
inst✝⁸ : Algebra C L
inst✝⁷ : IsIntegralClosure C A L
inst✝⁶ : Algebra A C
inst✝⁵ : IsScalarTower A C L
inst✝⁴ : FiniteDimensional K L
inst✝³ : IsDomain A
inst✝² : Algebra.IsSeparable K L
inst✝¹ : IsIntegrallyClosed A
inst✝ : IsNoetherianRing A
⊢ IsNoetherian A C

Tactic:
have := Classical.decEq L

Goal state after:
A : Type u_1
K : Type u_2
inst✝¹⁷ : CommRing A
inst✝¹⁶ : Field K
inst✝¹⁵ : Algebra A K
inst✝¹⁴ : IsFractionRing A K
L : Type u_3
inst✝¹³ : Field L
C : Type u_4
inst✝¹² : CommRing C
inst✝¹¹ : Algebra K L
inst✝¹⁰ : Algebra A L
inst✝⁹ : IsScalarTower A K L
inst✝⁸ : Algebra C L
inst✝⁷ : IsIntegralClosure C A L
inst✝⁶ : Algebra A C
inst✝⁵ : IsScalarTower A C L
inst✝⁴ : FiniteDimensional K L
inst✝³ : IsDomain A
inst✝² : Algebra.IsSeparable K L
inst✝¹ : IsIntegrallyClosed A
inst✝ : IsNoetherianRing A
this : DecidableEq L
⊢ IsNoetherian A C
Module: Mathlib.RingTheory.Trace.Basic

Goal state before:
pp: case pos
K : Type u_4
L : Type u_5
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
F : Type u_6
inst✝¹ : Field F
inst✝ : Algebra K F
x : L
hf : (Polynomial.map (algebraMap K F) (minpoly K x)).Splits
injKxL : Function.Injective ⇑(algebraMap (↥K⟮x⟯) L)
hx : IsIntegral K x
⊢ (algebraMap K F) ((Algebra.trace K ↥K⟮x⟯) (gen K x)) = ((minpoly K x).aroots F).sum

Tactic:
← adjoin.powerBasis_gen hx,

Goal state after:
case pos
K : Type u_4
L : Type u_5
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
F : Type u_6
inst✝¹ : Field F
inst✝ : Algebra K F
x : L
hf : (Polynomial.map (algebraMap K F) (minpoly K x)).Splits
injKxL : Function.Injective ⇑(algebraMap (↥K⟮x⟯) L)
hx : IsIntegral K x
⊢ (algebraMap K F) ((Algebra.trace K ↥K⟮x⟯) (adjoin.powerBasis hx).gen) = ((minpoly K x).aroots F).sum
Module: Mathlib.RingTheory.Trace.Basic

Goal state before:
pp: K : Type u_4
L : Type u_5
inst✝⁷ : Field K
inst✝⁶ : Field L
inst✝⁵ : Algebra K L
E : Type u_7
inst✝⁴ : Field E
inst✝³ : Algebra K E
inst✝² : IsAlgClosed E
inst✝¹ : FiniteDimensional K L
inst✝ : Algebra.IsSeparable K L
x : L
hx : IsIntegral K x
pb : PowerBasis K ↥K⟮x⟯ := adjoin.powerBasis hx
⊢ (algebraMap K E) ((algebraMap ℕ K) (finrank (↥K⟮x⟯) L)) *
      (algebraMap K E) ((Algebra.trace K ↥K⟮x⟯) (AdjoinSimple.gen K x)) =
    ∑ σ, σ x

Tactic:
← adjoin.powerBasis_gen hx,

Goal state after:
K : Type u_4
L : Type u_5
inst✝⁷ : Field K
inst✝⁶ : Field L
inst✝⁵ : Algebra K L
E : Type u_7
inst✝⁴ : Field E
inst✝³ : Algebra K E
inst✝² : IsAlgClosed E
inst✝¹ : FiniteDimensional K L
inst✝ : Algebra.IsSeparable K L
x : L
hx : IsIntegral K x
pb : PowerBasis K ↥K⟮x⟯ := adjoin.powerBasis hx
⊢ (algebraMap K E) ((algebraMap ℕ K) (finrank (↥K⟮x⟯) L)) *
      (algebraMap K E) ((Algebra.trace K ↥K⟮x⟯) (adjoin.powerBasis hx).gen) =
    ∑ σ, σ x
Module: Mathlib.RingTheory.Trace.Basic

Goal state before:
pp: case e_f.e_f
κ : Type w
A : Type u
B : Type v
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Fintype κ
b : κ → B
P : Matrix κ κ A
α β x : κ
⊢ (fun x_1 ↦ ((traceForm A B) (b x_1 * P.map (⇑(algebraMap A B)) x_1 α)) (b x * P.map (⇑(algebraMap A B)) x β)) =
    fun i ↦ Pᵀ α i * traceMatrix A b i x * P x β

Tactic:
ext y

Goal state after:
case e_f.e_f
κ : Type w
A : Type u
B : Type v
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Fintype κ
b : κ → B
P : Matrix κ κ A
α β x y : κ
⊢ ((traceForm A B) (b y * P.map (⇑(algebraMap A B)) y α)) (b x * P.map (⇑(algebraMap A B)) x β) =
    Pᵀ α y * traceMatrix A b y x * P x β
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝² : CommRing K
inst✝¹ : IsDomain K
inst✝ : Fintype Kˣ
⊢ ∏ x, x = -1

Tactic:
classical
    have : (∏ x ∈ (@univ Kˣ _).erase (-1), x) = 1 :=
      prod_involution (fun x _ => x⁻¹) (by simp)
        (fun a => by simp +contextual [Units.inv_eq_self_iff])
        (fun a => by simp [@inv_eq_iff_eq_inv _ _ a]) (by simp)
    rw [← insert_erase (mem_univ (-1 : Kˣ)), prod_insert (notMem_erase _ _), this, mul_one]

Goal state after:
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: case inl
K : Type u_1
inst✝³ : Ring K
inst✝² : NoZeroDivisors K
inst✝¹ : Nontrivial K
G : Subgroup Kˣ
inst✝ : Fintype ↥G
n : ℕ := Fintype.card ↥G
nzero : ↑(Fintype.card ↥G) = 0
p : ℕ
char_p : CharP K p
hd : p ∣ n
pprime : Nat.Prime p
fact_pprime : Fact (Nat.Prime p)
x : ↥G
hx : orderOf x = p
⊢ False

Tactic:
let u := ((x : Kˣ) : K)

Goal state after:
case inl
K : Type u_1
inst✝³ : Ring K
inst✝² : NoZeroDivisors K
inst✝¹ : Nontrivial K
G : Subgroup Kˣ
inst✝ : Fintype ↥G
n : ℕ := Fintype.card ↥G
nzero : ↑(Fintype.card ↥G) = 0
p : ℕ
char_p : CharP K p
hd : p ∣ n
pprime : Nat.Prime p
fact_pprime : Fact (Nat.Prime p)
x : ↥G
hx : orderOf x = p
u : K := ↑↑x
⊢ False
Module: Mathlib.RingTheory.Invariant.Basic

Goal state before:
pp: case neg
A : Type u_1
B : Type u_2
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : NoZeroDivisors B
b : B
i j : ℕ
p : A[X]
h : map (algebraMap A B) p = (X - C b) ^ i * X ^ j
f : B ≃ₐ[A] B
hi : i ≠ 0
ha : ¬b = 0
hf : (b - ↑↑f b) ^ i = 0
⊢ f b = b

Tactic:
pow_eq_zero_iff hi,

Goal state after:
case neg
A : Type u_1
B : Type u_2
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : NoZeroDivisors B
b : B
i j : ℕ
p : A[X]
h : map (algebraMap A B) p = (X - C b) ^ i * X ^ j
f : B ≃ₐ[A] B
hi : i ≠ 0
ha : ¬b = 0
hf : b - ↑↑f b = 0
⊢ f b = b