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

Goal state before:
pp: α : Type u_1
M : Matroid α
I K : Set α
hK : K ⊆ M.coloops
⊢ M.Indep (I \ K ∪ K) ↔ M.Indep I

Tactic:
sdiff_union_self,

Goal state after:
α : Type u_1
M : Matroid α
I K : Set α
hK : K ⊆ M.coloops
⊢ M.Indep (I ∪ K) ↔ M.Indep I
Module: Mathlib.Combinatorics.Matroid.Loop

Goal state before:
pp: α : Type u_1
M : Matroid α
e : α
inst✝ : M.Loopless
he : e ∈ M.E
⊢ e ∉ ∅

Tactic:
exact notMem_empty _

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

Goal state before:
pp: α : Type u_1
M : Matroid α
I : Set α
⊢ M.Indep I → I ⊆ {e | M.IsNonloop e}

Tactic:
exact fun h e ↦ h.isNonloop_of_mem

Goal state after:
Module: Mathlib.RingTheory.Algebraic.MvPolynomial

Goal state before:
pp: σ : Type u_1
R : Type u_2
inst✝ : CommRing R
i : σ
s : Set σ
h : i ∉ s
f : R[X]
g : MvPolynomial (↑s) R[X] →ₐ[R] MvPolynomial (↑s) R[X] := ⋯
hf : Function.Injective ⇑g
u : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R := ⋯
v : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R := ⋯
⊢ Function.Injective (⇑(optionEquivRight R ↑s) ∘ ⇑(optionEquivLeft R ↑s).symm)

Tactic:
simp only [EquivLike.comp_injective, EquivLike.injective]

Goal state after:
Module: Mathlib.RingTheory.Algebraic.MvPolynomial

Goal state before:
pp: case hC
σ : Type u_1
R : Type u_2
inst✝ : CommRing R
i : σ
s : Set σ
h : i ∉ s
f : R[X]
g : MvPolynomial (↑s) R[X] →ₐ[R] MvPolynomial (↑s) R[X] := ⋯
u : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R := ⋯
v : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R := ⋯
hf : Function.Injective ⇑u
h1 :
  Polynomial.aeval (X i) =
    ((supported R (insert i s)).val.comp ↑(supportedEquivMvPolynomial (insert i s)).symm).comp
      (Polynomial.aeval (X ⟨i, ⋯⟩))
⊢ ((((supported R (insert i s)).val.comp
                  ↑(((optionEquivRight R ↑s).symm.trans (renameEquiv R (Set.subtypeInsertEquivOption h).symm)).trans
                      (supportedEquivMvPolynomial (insert i s)).symm)).comp
              (mapAlgHom (Polynomial.aeval f))).comp
          ↑((optionEquivLeft R ↑s).symm.trans (optionEquivRight R ↑s))).comp
      CAlgHom =
    ((AlgHom.restrictScalars R (Polynomial.aeval ((Polynomial.aeval (X i)) f))).comp
          ↑(Polynomial.mapAlgEquiv (supportedEquivMvPolynomial s).symm)).comp
      CAlgHom

Tactic:
ext1
      simp [Set.subtypeInsertEquivOption, Subalgebra.algebraMap_eq, optionEquivLeft_symm_apply]

Goal state after:
Module: Mathlib.RingTheory.Algebraic.MvPolynomial

Goal state before:
pp: σ : Type u_1
R : Type u_2
inst✝ : CommRing R
i : σ
s : Set σ
h : i ∉ s
f : R[X]
g : MvPolynomial (↑s) R[X] →ₐ[R] MvPolynomial (↑s) R[X] := mapAlgHom (Polynomial.aeval f)
u : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R :=
  (((supported R (insert i s)).val.comp
            ↑(((optionEquivRight R ↑s).symm.trans (renameEquiv R (Set.subtypeInsertEquivOption h).symm)).trans
                (supportedEquivMvPolynomial (insert i s)).symm)).comp
        g).comp
    ↑((optionEquivLeft R ↑s).symm.trans (optionEquivRight R ↑s))
v : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R :=
  (AlgHom.restrictScalars R (Polynomial.aeval ((Polynomial.aeval (X i)) f))).comp
    ↑(Polynomial.mapAlgEquiv (supportedEquivMvPolynomial s).symm)
hf : Function.Injective ⇑u
h1 :
  Polynomial.aeval (X i) =
    ((supported R (insert i s)).val.comp ↑(supportedEquivMvPolynomial (insert i s)).symm).comp
      (Polynomial.aeval (X ⟨i, ⋯⟩))
⊢ Function.Injective ⇑(Polynomial.aeval ((Polynomial.aeval (X i)) f))

Tactic:
have h2 : u = v := by
    simp only [u, v, g]
    ext1
    · ext1
      simp [Set.subtypeInsertEquivOption, Subalgebra.algebraMap_eq, optionEquivLeft_symm_apply]
    · simp [Set.subtypeInsertEquivOption, h1, optionEquivLeft_symm_apply]

Goal state after:
σ : Type u_1
R : Type u_2
inst✝ : CommRing R
i : σ
s : Set σ
h : i ∉ s
f : R[X]
g : MvPolynomial (↑s) R[X] →ₐ[R] MvPolynomial (↑s) R[X] := mapAlgHom (Polynomial.aeval f)
u : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R :=
  (((supported R (insert i s)).val.comp
            ↑(((optionEquivRight R ↑s).symm.trans (renameEquiv R (Set.subtypeInsertEquivOption h).symm)).trans
                (supportedEquivMvPolynomial (insert i s)).symm)).comp
        g).comp
    ↑((optionEquivLeft R ↑s).symm.trans (optionEquivRight R ↑s))
v : (MvPolynomial (↑s) R)[X] →ₐ[R] MvPolynomial σ R :=
  (AlgHom.restrictScalars R (Polynomial.aeval ((Polynomial.aeval (X i)) f))).comp
    ↑(Polynomial.mapAlgEquiv (supportedEquivMvPolynomial s).symm)
hf : Function.Injective ⇑u
h1 :
  Polynomial.aeval (X i) =
    ((supported R (insert i s)).val.comp ↑(supportedEquivMvPolynomial (insert i s)).symm).comp
      (Polynomial.aeval (X ⟨i, ⋯⟩))
h2 : u = v
⊢ Function.Injective ⇑(Polynomial.aeval ((Polynomial.aeval (X i)) f))
Module: Mathlib.Combinatorics.Matroid.Closure

Goal state before:
pp: α : Type u_2
M : Matroid α
X : Set α
e f : α
B : Set α
hB : M.IsBasis B X
he : e ∈ M.closure (insert f B \ {e})
heB : e ∈ insert f B
hfX : f ∈ X
⊢ M.IsBasis (insert f B \ {e}) X

Tactic:
rw [isBasis_iff_indep_closure] at hB ⊢
  exact ⟨hB.1.indep_insert_sdiff_of_mem_closure (hB.2.1 hfX) he heB, hB.2.1.trans_eq
    (hB.1.closure_insert_sdiff_eq_of_mem_closure (hB.2.1 hfX) he).symm, sdiff_subset.trans
    (insert_subset hfX hB.2.2)⟩

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

Goal state before:
pp: R : Type u_1
A : Type w
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
⊢ trdeg R A = ⨆ ι, #↑↑ι

Tactic:
refine (ciSup_le' fun s ↦ ?_).antisymm
    (ciSup_le' fun s ↦ le_ciSup_of_le bddAbove_of_small ⟨s, s.2.1⟩ le_rfl)
  choose t ht using exists_isTranscendenceBasis_superset s.2
  exact le_ciSup_of_le bddAbove_of_small ⟨t, ht.2⟩ (mk_le_mk_of_subset ht.1)

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

Goal state before:
pp: M : Type u_1
α : Type u_2
inst✝¹ : Group M
inst✝ : MulAction M α
s : Set α
m : M
⊢ m ∈ fixingSubgroup M s ↔ s ⊆ fixedBy α m

Tactic:
by
  simp_rw [mem_fixingSubgroup_iff, Set.subset_def, mem_fixedBy]

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

Goal state before:
pp: case inr
ι : Type u
ι' : Type u'
R : Type u_1
S : Type v
A : Type w
x : ι → A
y : ι' → A
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing A
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R A
inst✝³ : Algebra S A
inst✝² : IsScalarTower R S A
inst✝¹ : FaithfulSMul R A
inst✝ : NoZeroDivisors A
I B : Set A
I_ind : AlgebraicIndepOn R _root_.id I
h : ∀ x ∈ B \ I, ¬AlgebraicIndepOn R _root_.id (insert x I)
h✝ : Nontrivial R
B_base : Algebra.IsAlgebraic (↥(adjoin R (range Subtype.val))) A
⊢ Algebra.IsAlgebraic (↥(adjoin R (range fun i ↦ ↑i))) A

Tactic:
rw [Subtype.range_val] at B_base ⊢

Goal state after:
case inr
ι : Type u
ι' : Type u'
R : Type u_1
S : Type v
A : Type w
x : ι → A
y : ι' → A
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing A
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R A
inst✝³ : Algebra S A
inst✝² : IsScalarTower R S A
inst✝¹ : FaithfulSMul R A
inst✝ : NoZeroDivisors A
I B : Set A
I_ind : AlgebraicIndepOn R _root_.id I
h : ∀ x ∈ B \ I, ¬AlgebraicIndepOn R _root_.id (insert x I)
h✝ : Nontrivial R
B_base : Algebra.IsAlgebraic (↥(adjoin R B)) A
⊢ Algebra.IsAlgebraic (↥(adjoin R I)) A
Module: Mathlib.RingTheory.AlgebraicIndependent.TranscendenceBasis

Goal state before:
pp: case inl
R : Type u_1
A : Type w
inst✝⁴ : CommRing R
inst✝³ : CommRing A
inst✝² : Algebra R A
inst✝¹ : FaithfulSMul R A
inst✝ : NoZeroDivisors A
s t : Set A
a : A
h : (matroid R A).IsBasis s t
h✝ : Subsingleton A
⊢ IsAlgebraic (↥(adjoin R s)) a ↔ IsAlgebraic (↥(adjoin R t)) a

Tactic:
apply iff_of_false

Goal state after:
case inl.ha
R : Type u_1
A : Type w
inst✝⁴ : CommRing R
inst✝³ : CommRing A
inst✝² : Algebra R A
inst✝¹ : FaithfulSMul R A
inst✝ : NoZeroDivisors A
s t : Set A
a : A
h : (matroid R A).IsBasis s t
h✝ : Subsingleton A
⊢ ¬IsAlgebraic (↥(adjoin R s)) a

case inl.hb
R : Type u_1
A : Type w
inst✝⁴ : CommRing R
inst✝³ : CommRing A
inst✝² : Algebra R A
inst✝¹ : FaithfulSMul R A
inst✝ : NoZeroDivisors A
s t : Set A
a : A
h : (matroid R A).IsBasis s t
h✝ : Subsingleton A
⊢ ¬IsAlgebraic (↥(adjoin R t)) a
Module: Mathlib.FieldTheory.SeparableDegree

Goal state before:
pp: case neg.refine_1
F : Type u
inst✝ : Field F
f g : F[X]
h : ¬f = 0 ∧ ¬g = 0
H : ∀ (a : AlgebraicClosure F), f ≠ 0 ∧ (aeval a) f = 0 → ∀ (b : AlgebraicClosure F), g ≠ 0 ∧ (aeval b) g = 0 → a ≠ b
u : F[X]
hu : Irreducible u
x✝¹ : u ∣ f
x✝ : u ∣ g
v : F[X]
hf : f = u * v
w : F[X]
hg : g = u * w
⊢ False

pp: case neg.refine_2
F : Type u
inst✝ : Field F
f g : F[X]
h : ¬f = 0 ∧ ¬g = 0
⊢ f = 0 ∧ g = 0 ∨ IsCoprime f g →
    ∀ (a : AlgebraicClosure F), f ≠ 0 ∧ (aeval a) f = 0 → ∀ (b : AlgebraicClosure F), g ≠ 0 ∧ (aeval b) g = 0 → a ≠ b

Tactic:
· obtain ⟨x, hx⟩ := IsAlgClosed.exists_aeval_eq_zero
      (AlgebraicClosure F) _ (degree_pos_of_irreducible hu).ne'
    exact H x ⟨h.1, by simpa only [map_mul, hx, zero_mul] using congr(aeval x $hf)⟩
      x ⟨h.2, by simpa only [map_mul, hx, zero_mul] using congr(aeval x $hg)⟩ rfl

Goal state after:
case neg.refine_2
F : Type u
inst✝ : Field F
f g : F[X]
h : ¬f = 0 ∧ ¬g = 0
⊢ f = 0 ∧ g = 0 ∨ IsCoprime f g →
    ∀ (a : AlgebraicClosure F), f ≠ 0 ∧ (aeval a) f = 0 → ∀ (b : AlgebraicClosure F), g ≠ 0 ∧ (aeval b) g = 0 → a ≠ b
Module: Mathlib.RingTheory.AlgebraicIndependent.TranscendenceBasis

Goal state before:
pp: case inr.inr
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
⊢ IsTranscendenceBasis R fun x ↦ v ↑x

Tactic:
have hi' : v i ∉ v '' s := fun his ↦ Hj <| 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:
case inr.inr
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
hi' : v i ∉ v '' s
⊢ IsTranscendenceBasis R fun x ↦ v ↑x
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: F : Type u_1
inst✝⁶ : Field F
E : Type u_2
inst✝⁵ : Field E
inst✝⁴ : Algebra F E
p : F[X]
hFE : FiniteDimensional F E
sp : Polynomial.IsSplittingField F E p
hp : p.Separable
K : Type u_3
inst✝³ : Field K
inst✝² : Algebra F K
inst✝¹ : Algebra K E
inst✝ : IsScalarTower F K E
x : E
hx : x ∈ p.aroots E
h : IsIntegral K x
h1 : p ≠ 0
h2 : minpoly K x ∣ Polynomial.map (algebraMap F K) p
key_equiv : (↥(IntermediateField.restrictScalars F K⟮x⟯) →ₐ[F] E) ≃ (f : K →ₐ[F] E) × (↥K⟮x⟯ →ₐ[K] E) := ⋯
this✝ : ∀ (f : K →ₐ[F] E), Finite (↥K⟮x⟯ →ₐ[K] E)
this : FiniteDimensional F K
⊢ ∀ x_1 ∈ Finset.univ, Nat.card (↥K⟮x⟯ →ₐ[K] E) = (minpoly K x).natDegree

Tactic:
intro f

Goal state after:
F : Type u_1
inst✝⁶ : Field F
E : Type u_2
inst✝⁵ : Field E
inst✝⁴ : Algebra F E
p : F[X]
hFE : FiniteDimensional F E
sp : Polynomial.IsSplittingField F E p
hp : p.Separable
K : Type u_3
inst✝³ : Field K
inst✝² : Algebra F K
inst✝¹ : Algebra K E
inst✝ : IsScalarTower F K E
x : E
hx : x ∈ p.aroots E
h : IsIntegral K x
h1 : p ≠ 0
h2 : minpoly K x ∣ Polynomial.map (algebraMap F K) p
key_equiv : (↥(IntermediateField.restrictScalars F K⟮x⟯) →ₐ[F] E) ≃ (f : K →ₐ[F] E) × (↥K⟮x⟯ →ₐ[K] E) :=
  id algHomEquivSigma
this✝ : ∀ (f : K →ₐ[F] E), Finite (↥K⟮x⟯ →ₐ[K] E)
this : FiniteDimensional F K
f : K →ₐ[F] E
⊢ f ∈ Finset.univ → Nat.card (↥K⟮x⟯ →ₐ[K] E) = (minpoly K x).natDegree
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: case h_splits
F : Type u_1
inst✝⁶ : Field F
E : Type u_2
inst✝⁵ : Field E
inst✝⁴ : Algebra F E
p : F[X]
hFE : FiniteDimensional F E
sp : Polynomial.IsSplittingField F E p
hp : p.Separable
K : Type u_3
inst✝³ : Field K
inst✝² : Algebra F K
inst✝¹ : Algebra K E
inst✝ : IsScalarTower F K E
x : E
hx : x ∈ p.aroots E
h : IsIntegral K x
h1 : p ≠ 0
h2 : minpoly K x ∣ Polynomial.map (algebraMap F K) p
key_equiv : (↥(IntermediateField.restrictScalars F K⟮x⟯) →ₐ[F] E) ≃ (f : K →ₐ[F] E) × (↥K⟮x⟯ →ₐ[K] E) :=
  id algHomEquivSigma
this✝ : ∀ (f : K →ₐ[F] E), Finite (↥K⟮x⟯ →ₐ[K] E)
this : FiniteDimensional F K
f : K →ₐ[F] E
a✝ : f ∈ Finset.univ
⊢ Polynomial.map (algebraMap K E) (minpoly K x) ∣ Polynomial.map ((↑f).comp (algebraMap F K)) p

Tactic:
← p.map_map,

Goal state after:
case h_splits
F : Type u_1
inst✝⁶ : Field F
E : Type u_2
inst✝⁵ : Field E
inst✝⁴ : Algebra F E
p : F[X]
hFE : FiniteDimensional F E
sp : Polynomial.IsSplittingField F E p
hp : p.Separable
K : Type u_3
inst✝³ : Field K
inst✝² : Algebra F K
inst✝¹ : Algebra K E
inst✝ : IsScalarTower F K E
x : E
hx : x ∈ p.aroots E
h : IsIntegral K x
h1 : p ≠ 0
h2 : minpoly K x ∣ Polynomial.map (algebraMap F K) p
key_equiv : (↥(IntermediateField.restrictScalars F K⟮x⟯) →ₐ[F] E) ≃ (f : K →ₐ[F] E) × (↥K⟮x⟯ →ₐ[K] E) :=
  id algHomEquivSigma
this✝ : ∀ (f : K →ₐ[F] E), Finite (↥K⟮x⟯ →ₐ[K] E)
this : FiniteDimensional F K
f : K →ₐ[F] E
a✝ : f ∈ Finset.univ
⊢ Polynomial.map (algebraMap K E) (minpoly K x) ∣ Polynomial.map (↑f) (Polynomial.map (algebraMap F K) p)
Module: Mathlib.Topology.Algebra.Group.ClosedSubgroup

Goal state before:
pp: G : Type u
inst✝² : Group G
inst✝¹ : TopologicalSpace G
inst✝ : SeparatelyContinuousMul G
H : Subgroup G
h : IsClosed ↑H
⊢ IsClosed ↑H.normalCore

Tactic:
by
  rw [normalCore_eq_iInf_comap_conj]
  push_cast
  apply isClosed_iInter
  intro g
  exact h.preimage (IsTopologicalGroup.continuous_conj g)

Goal state after:
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

Goal state after:
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
f : Gal(K/k)
⊢ f ∈ σ • ↑(adjoin k {y}).fixingSubgroup → f ∈ (↑L.fixingSubgroup)ᶜ
Module: Mathlib.FieldTheory.Galois.Infinite

Goal state before:
pp: 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
x : K
hx : ∀ f ∈ L.fixingSubgroup, f x = x
mem : x ∈ (adjoin ↥L {x}).toIntermediateField
this : IntermediateField.fixedField ⊤ = ⊥
⊢ ∀ f ∈ ⊤, f ⟨x, mem⟩ = ⟨x, mem⟩

Tactic:
intro f

Goal state after:
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
x : K
hx : ∀ f ∈ L.fixingSubgroup, f x = x
mem : x ∈ (adjoin ↥L {x}).toIntermediateField
this : IntermediateField.fixedField ⊤ = ⊥
f : Gal(↥(adjoin ↥L {x}).toIntermediateField/↥L)
⊢ f ∈ ⊤ → f ⟨x, mem⟩ = ⟨x, mem⟩
Module: Mathlib.LinearAlgebra.BilinearForm.DualLattice

Goal state before:
pp: R : Type u_4
S : Type u_2
M : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : Field S
inst✝⁵ : AddCommGroup M
inst✝⁴ : Algebra R S
inst✝³ : Module R M
inst✝² : Module S M
inst✝¹ : IsScalarTower R S M
B : BilinForm S M
ι : Type u_1
inst✝ : Finite ι
hB : B.Nondegenerate
b : Basis ι S M
⊢ B.flip.dualSubmodule (B.dualSubmodule (Submodule.span R (Set.range ⇑b))) = Submodule.span R (Set.range ⇑b)

Tactic:
classical
  let := b.finiteDimensional_of_finite
  rw [dualSubmodule_span_of_basis B hB, dualSubmodule_span_of_basis _ hB.flip,
    dualBasis_flip_dualBasis hB]

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

Goal state before:
pp: case refine_2
k : Type u_1
K : Type u_2
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
H : Subgroup Gal(K/k)
L : IntermediateField k K
inst✝ : Normal k ↥L
x : K
xL : x ∈ L
h : ∀ a ∈ H, ((restrictNormalHom ↥L) a) ⟨x, xL⟩ = ⟨x, xL⟩
⊢ x ∈ ↑(fixedField H ⊓ L)

Tactic:
simp only [coe_inf, Set.mem_inter_iff, SetLike.mem_coe, mem_fixedField_iff, xL, and_true]

Goal state after:
case refine_2
k : Type u_1
K : Type u_2
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
H : Subgroup Gal(K/k)
L : IntermediateField k K
inst✝ : Normal k ↥L
x : K
xL : x ∈ L
h : ∀ a ∈ H, ((restrictNormalHom ↥L) a) ⟨x, xL⟩ = ⟨x, xL⟩
⊢ ∀ f ∈ H, f x = x
Module: Mathlib.RingTheory.Trace.Defs

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing T
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
ι : Type u_4
κ : Type u_5
inst✝¹ : Finite ι
inst✝ : Finite κ
b : Basis ι R S
c : Basis κ S T
x : T
this : DecidableEq ι
⊢ (trace R S) ((trace S T) x) = (trace R T) x

Tactic:
have := Classical.decEq κ

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing T
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
ι : Type u_4
κ : Type u_5
inst✝¹ : Finite ι
inst✝ : Finite κ
b : Basis ι R S
c : Basis κ S T
x : T
this✝ : DecidableEq ι
this : DecidableEq κ
⊢ (trace R S) ((trace S T) x) = (trace R T) x
Module: Mathlib.FieldTheory.PurelyInseparable.Basic

Goal state before:
pp: F : Type u
E : Type v
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
L : IntermediateField F E
h : IsPurelyInseparable (↥L) E
x : E
hx : x ∈ separableClosure F E
⊢ x ∈ L

Tactic:
obtain ⟨y, rfl⟩ := h.inseparable' _ <|
    IsSeparable.tower_top L (mem_separableClosure_iff.1 hx)

Goal state after:
F : Type u
E : Type v
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
L : IntermediateField F E
h : IsPurelyInseparable (↥L) E
y : ↥L
hx : (algebraMap (↥L) E) y ∈ separableClosure F E
⊢ (algebraMap (↥L) E) y ∈ L
Module: Mathlib.RingTheory.Trace.Basic

Goal state before:
pp: K : Type u_4
L : Type u_5
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : FiniteDimensional K L
x : L
⊢ (Algebra.trace K ↥K⟮x⟯) ((Algebra.trace (↥K⟮x⟯) L) ((algebraMap (↥K⟮x⟯) L) (AdjoinSimple.gen K x))) =
    finrank (↥K⟮x⟯) L • (Algebra.trace K ↥K⟮x⟯) (AdjoinSimple.gen K x)

Tactic:
rw [trace_algebraMap, LinearMap.map_smul_of_tower]

Goal state after:
Module: Mathlib.RingTheory.Invariant.Basic

Goal state before:
pp: A : Type u_1
B : Type u_2
G : Type u_3
inst✝⁷ : CommRing A
inst✝⁶ : CommRing B
inst✝⁵ : Algebra A B
inst✝⁴ : Group G
inst✝³ : MulSemiringAction G B
inst✝² : IsInvariant A B G
inst✝¹ : Finite G
inst✝ : SMulCommClass G A B
P : Ideal A
Q : Ideal B
hP : Q.LiesOver P
hQ : Q.IsPrime
R : Ideal B
h : R ∈ P.primesOver B
this : R.IsPrime
g : G
hg : R = g • Q
⊢ R ∈ MulAction.orbit G Q

Tactic:
exact ⟨g, hg.symm⟩

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

Goal state before:
pp: K : Type u_1
inst✝² : Field K
inst✝¹ : Fintype K
p : ℕ
inst✝ : CharP K p
hp : Fact (Nat.Prime p)
this : Module (ZMod p) K :=
  let __src := (ZMod.castHom ⋯ K).toModule;
  __src
h : q = p ^ 0
⊢ False

Tactic:
pow_zero

Goal state after:
K : Type u_1
inst✝² : Field K
inst✝¹ : Fintype K
p : ℕ
inst✝ : CharP K p
hp : Fact (Nat.Prime p)
this : Module (ZMod p) K :=
  let __src := (ZMod.castHom ⋯ K).toModule;
  __src
h : q = 1
⊢ False
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: case pos
K : Type u_1
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : DecidableEq K
i : ℕ
φ : Kˣ →* K := { toFun := fun x ↦ ↑x ^ i, map_one' := ⋯, map_mul' := ⋯ }
this✝ : Decidable (φ = 1)
this : q - 1 ∣ i ↔ φ = 1
h✝ : φ = 1
⊢ ↑(Fintype.card Kˣ) = -1

Tactic:
rw [Fintype.card_units, Nat.cast_sub,
              cast_card_eq_zero, Nat.cast_one, zero_sub]

Goal state after:
case pos
K : Type u_1
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : DecidableEq K
i : ℕ
φ : Kˣ →* K := { toFun := fun x ↦ ↑x ^ i, map_one' := ⋯, map_mul' := ⋯ }
this✝ : Decidable (φ = 1)
this : q - 1 ∣ i ↔ φ = 1
h✝ : φ = 1
⊢ 1 ≤ q
Module: Mathlib.RingTheory.Int.Basic

Goal state before:
pp: m n : ℤ
p : ℕ
hp : Nat.Prime p
h : ↑p ∣ m * n
⊢ p ∣ m.natAbs ∨ p ∣ n.natAbs

Tactic:
rwa [← hp.dvd_mul, ← Int.natAbs_mul, ← Int.natCast_dvd]

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

Goal state before:
pp: G : Type u_1
G' : Type u_2
inst✝¹⁹ : Group G
inst✝¹⁸ : Group G'
A : Type u_5
B : Type u_6
C : Type u_7
inst✝¹⁷ : CommRing A
inst✝¹⁶ : CommRing B
inst✝¹⁵ : CommRing C
inst✝¹⁴ : IsDomain C
inst✝¹³ : Algebra A B
inst✝¹² : Algebra A C
inst✝¹¹ : Algebra B C
inst✝¹⁰ : FaithfulSMul A B
inst✝⁹ : FaithfulSMul B C
inst✝⁸ : IsScalarTower A B C
inst✝⁷ : Finite G
inst✝⁶ : Finite G'
N : Subgroup G
inst✝⁵ : N.Normal
inst✝⁴ : MulSemiringAction G C
inst✝³ : IsGaloisGroup G A C
inst✝² : IsGaloisGroup (↥N) B C
inst✝¹ : MulSemiringAction G' B
inst✝ : IsGaloisGroup G' A B
g : G
x : B
⊢ (algebraMap B C) ((quotientMulEquiv G G' A B C N) ↑g • x) = g • (algebraMap B C) x

Tactic:
have : IsDomain B := (FaithfulSMul.algebraMap_injective B C).isDomain
  let := mulSemiringActionOfNormal G B C N
  let := mulSemiringActionQuotient G B C N
  have := smulCommClassQuotient G A B C N
  have := quotient G A B C N
  rw [← algebraMap_smulOfNormal G B C N g x]
  congr
  apply mulEquivCongr_apply_smul

Goal state after: