mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.GroupTheory.GroupAction.FixedPoints

Goal state before:
pp: α : Type u_1
G : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
g h : G
comm : Commute g h
x : α
⊢ h⁻¹ • x ∈ fixedBy α g ↔ x ∈ fixedBy α g

Tactic:
mem_fixedBy,

Goal state after:
α : Type u_1
G : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
g h : G
comm : Commute g h
x : α
⊢ g • h⁻¹ • x = h⁻¹ • x ↔ x ∈ fixedBy α g
Module: Mathlib.GroupTheory.GroupAction.FixedPoints

Goal state before:
pp: α : Type u_1
G : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
g h : G
comm : Commute g h
⊢ (fixedBy α g)ᶜ ∈ fixedBy (Set α) h

Tactic:
mem_fixedBy,

Goal state after:
α : Type u_1
G : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
g h : G
comm : Commute g h
⊢ h • (fixedBy α g)ᶜ = (fixedBy α g)ᶜ
Module: Mathlib.FieldTheory.SeparableDegree

Goal state before:
pp: F : Type u
inst✝ : Field F
f✝ f g : F[X]
h : f = 0 ∨ g = 0
hf : f = 0
⊢ g.natDegree = 0 ↔ 0 = 0 ∧ g = 0 ∨ ∃ r, IsUnit r ∧ C r = g

Tactic:
natDegree_eq_zero

Goal state after:
F : Type u
inst✝ : Field F
f✝ f g : F[X]
h : f = 0 ∨ g = 0
hf : f = 0
⊢ (∃ x, C x = g) ↔ 0 = 0 ∧ g = 0 ∨ ∃ r, IsUnit r ∧ C r = g
Module: Mathlib.Topology.Algebra.FilterBasis

Goal state before:
pp: G : Type u
inst✝ : Group G
B : GroupFilterBasis G
U : Set G
hU : U ∈ B
⊢ U ∈ 𝓝 1

Tactic:
B.nhds_one_hasBasis.mem_iff

Goal state after:
G : Type u
inst✝ : Group G
B : GroupFilterBasis G
U : Set G
hU : U ∈ B
⊢ ∃ i ∈ B, id i ⊆ U
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: F : Type u_1
inst✝⁴ : Field F
E : Type u_2
inst✝³ : Field E
inst✝² : Algebra F E
inst✝¹ : FiniteDimensional F E
inst✝ : IsGalois F E
⊢ Nat.card Gal(E/F) = finrank F E

Tactic:
obtain ⟨α, hα⟩ := Field.exists_primitive_element F E
  let iso : F⟮α⟯ ≃ₐ[F] E :=
    { toFun := fun e => e.val
      invFun := fun e => ⟨e, by rw [hα]; exact IntermediateField.mem_top⟩
      map_mul' := fun _ _ => rfl
      map_add' := fun _ _ => rfl
      commutes' := fun _ => rfl }
  have H : IsIntegral F α := IsGalois.integral F α
  have h_sep : IsSeparable F α := IsGalois.separable F α
  have h_splits : ((minpoly F α).map (algebraMap F E)).Splits := IsGalois.splits F α
  replace h_splits : ((minpoly F α).map (algebraMap F F⟮α⟯)).Splits := by
    simpa [Polynomial.map_map] using! h_splits.map iso.symm.toRingHom
  rw [← LinearEquiv.finrank_eq iso.toLinearEquiv]
  rw [← IntermediateField.AdjoinSimple.card_aut_eq_finrank F E H h_sep h_splits]
  apply Nat.card_congr
  exact Equiv.mk (fun ϕ => iso.trans (ϕ.trans iso.symm)) fun ϕ => iso.symm.trans (ϕ.trans iso)

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
⊢ Algebra.IsSeparable F E

Tactic:
by
  rw [← isSeparable_top, ← (isSplittingField_iff_intermediateField.mp sp).2,
    isSeparable_adjoin_iff_isSeparable]
  exact fun x hx ↦ hp.of_dvd (minpoly.dvd F x (aeval_eq_zero_of_mem_rootSet hx))

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

Goal state before:
pp: case adjoin_rootSet'
F : Type u_1
inst✝⁴ : Field F
E : Type u_2
inst✝³ : Field E
inst✝² : Algebra F E
inst✝¹ : FiniteDimensional F E
inst✝ : IsGalois F E
α : E
h1 : F⟮α⟯ = ⊤
⊢ F⟮α⟯.toSubalgebra ≤ Algebra.adjoin F ((minpoly F α).rootSet E)

Tactic:
IntermediateField.adjoin_simple_toSubalgebra_of_isAlgebraic (integral F α).isAlgebraic

Goal state after:
case adjoin_rootSet'
F : Type u_1
inst✝⁴ : Field F
E : Type u_2
inst✝³ : Field E
inst✝² : Algebra F E
inst✝¹ : FiniteDimensional F E
inst✝ : IsGalois F E
α : E
h1 : F⟮α⟯ = ⊤
⊢ F[α] ≤ Algebra.adjoin F ((minpoly F α).rootSet E)
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: F : Type u_1
inst✝³ : Field F
E : Type u_2
inst✝² : Field E
inst✝¹ : Algebra F E
inst✝ : FiniteDimensional F E
tfae_1_to_2 : IsGalois F E → fixedField ⊤ = ⊥
tfae_1_to_3 : IsGalois F E → Nat.card Gal(E/F) = finrank F E
tfae_1_to_4 : IsGalois F E → ∃ p, p.Separable ∧ Polynomial.IsSplittingField F E p
⊢ [IsGalois F E, fixedField ⊤ = ⊥, Nat.card Gal(E/F) = finrank F E,
      ∃ p, p.Separable ∧ Polynomial.IsSplittingField F E p].TFAE

Tactic:
tfae_have 2 → 1 := of_fixedField_eq_bot F E

Goal state after:
F : Type u_1
inst✝³ : Field F
E : Type u_2
inst✝² : Field E
inst✝¹ : Algebra F E
inst✝ : FiniteDimensional F E
tfae_1_to_2 : IsGalois F E → fixedField ⊤ = ⊥
tfae_1_to_3 : IsGalois F E → Nat.card Gal(E/F) = finrank F E
tfae_1_to_4 : IsGalois F E → ∃ p, p.Separable ∧ Polynomial.IsSplittingField F E p
tfae_2_to_1 : fixedField ⊤ = ⊥ → IsGalois F E
⊢ [IsGalois F E, fixedField ⊤ = ⊥, Nat.card Gal(E/F) = finrank F E,
      ∃ p, p.Separable ∧ Polynomial.IsSplittingField F E p].TFAE
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
σ τ : Gal(L/K)
h_diff : σ ≠ τ
hστ : σ⁻¹ * τ ≠ 1
x : L
hx : (σ⁻¹ * τ) x ≠ x
E : IntermediateField K L := K⟮x⟯
this : FiniteDimensional K ↥K⟮x⟯
⊢ ∃ U, IsClopen U ∧ σ ∈ U ∧ τ ∈ Uᶜ

Tactic:
refine ⟨σ • E.fixingSubgroup,
    ⟨E.fixingSubgroup_isClosed.leftCoset σ, E.fixingSubgroup_isOpen.leftCoset σ⟩,
    ⟨1, E.fixingSubgroup.one_mem', mul_one σ⟩, ?_⟩

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
hστ : σ⁻¹ * τ ≠ 1
x : L
hx : (σ⁻¹ * τ) x ≠ x
E : IntermediateField K L := K⟮x⟯
this : FiniteDimensional K ↥K⟮x⟯
⊢ τ ∈ (σ • ↑E.fixingSubgroup)ᶜ
Module: Mathlib.FieldTheory.Galois.Basic

Goal state before:
pp: F : Type u_1
E' : Type u_3
inst✝³ : Field F
inst✝² : Field E'
inst✝¹ : Algebra F E'
inst✝ : IsGalois F E'
L : IntermediateField F E'
hnfd : FiniteDimensional F ↥L
E : IntermediateField F E' := normalClosure F (↥L) E'
hle : L ≤ E
L' : IntermediateField F ↥E := restrict hle
h : finrank F ↥L' = L'.fixingSubgroup.index
⊢ finrank F ↥L = L.fixingSubgroup.index

Tactic:
(restrictAlgEquiv hle).toLinearEquiv.finrank_eq,

Goal state after:
F : Type u_1
E' : Type u_3
inst✝³ : Field F
inst✝² : Field E'
inst✝¹ : Algebra F E'
inst✝ : IsGalois F E'
L : IntermediateField F E'
hnfd : FiniteDimensional F ↥L
E : IntermediateField F E' := normalClosure F (↥L) E'
hle : L ≤ E
L' : IntermediateField F ↥E := restrict hle
h : finrank F ↥L' = L'.fixingSubgroup.index
⊢ finrank F ↥(restrict hle) = L.fixingSubgroup.index
Module: Mathlib.LinearAlgebra.BilinearForm.DualLattice

Goal state before:
pp: R : Type u_1
S : Type u_2
M : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : Field S
inst✝⁶ : AddCommGroup M
inst✝⁵ : Algebra R S
inst✝⁴ : Module R M
inst✝³ : Module S M
inst✝² : IsScalarTower R S M
B : BilinForm S M
inst✝¹ : IsDomain R
hB : B.Nondegenerate
inst✝ : IsTorsionFree R S
N : Submodule R M
hN : Submodule.span S ↑N = ⊤
⊢ Function.Injective ⇑(B.dualSubmoduleToDual N)

Tactic:
intro x y e
  ext
  apply LinearMap.ker_eq_bot.mp hB.ker_eq_bot
  apply LinearMap.ext_on hN
  intro z hz
  simpa using congr_arg (algebraMap R S) (LinearMap.congr_fun e ⟨z, hz⟩)

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

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : IsDomain R
inst✝³ : Algebra R S
inst✝² : IsIntegrallyClosed R
inst✝¹ : IsDomain S
inst✝ : IsTorsionFree R S
x : S
hx : IsIntegral R x
a b : R[X]
h : (Polynomial.aeval x) (a * b) = 0
h' : ¬(Polynomial.aeval x) a = 0
⊢ (Polynomial.aeval x) b = 0

Tactic:
aeval_mul

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : IsDomain R
inst✝³ : Algebra R S
inst✝² : IsIntegrallyClosed R
inst✝¹ : IsDomain S
inst✝ : IsTorsionFree R S
x : S
hx : IsIntegral R x
a b : R[X]
h : (Polynomial.aeval x) a * (Polynomial.aeval x) b = 0
h' : ¬(Polynomial.aeval x) a = 0
⊢ (Polynomial.aeval x) b = 0
Module: Mathlib.FieldTheory.IsSepClosed

Goal state before:
pp: k : Type u
inst✝¹ : Field k
inst✝ : IsSepClosed k
x : k
n : ℕ
hn : NeZero ↑n
hn' : 0 < n
⊢ ∃ z, z ^ n = x

Tactic:
have : degree (X ^ n - C x) ≠ 0 := by
    rw [degree_X_pow_sub_C hn' x]
    exact (WithBot.coe_lt_coe.2 hn').ne'

Goal state after:
k : Type u
inst✝¹ : Field k
inst✝ : IsSepClosed k
x : k
n : ℕ
hn : NeZero ↑n
hn' : 0 < n
this : (X ^ n - C x).degree ≠ 0
⊢ ∃ z, z ^ n = x
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
inst✝ : IsGalois k K
H : (ClosedSubgroup Gal(K/k))ᵒᵈ
⊢ (fun L ↦ { toSubgroup := L.fixingSubgroup, isClosed' := ⋯ }) ((fun H ↦ IntermediateField.fixedField ↑H) H) = H

Tactic:
by
    simp_rw [fixingSubgroup_fixedField H]
    rfl

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

Goal state before:
pp: case h
k : Type u_1
K : Type u_2
R : Type u_3
inst✝⁶ : Field k
inst✝⁵ : Field K
inst✝⁴ : Algebra k K
inst✝³ : CommRing R
inst✝² : Algebra k R
inst✝¹ : IsPurelyInseparable k K
q : ℕ
inst✝ : ExpChar k q
a✝ : Nontrivial (R ⊗[k] K)
hq : Nat.Prime q
x : R
y : K
n : ℕ
a : k
ha : (algebraMap k K) a = y ^ q ^ n
this : (x ^ q ^ n) ⊗ₜ[k] (y ^ q ^ n) = (x ^ q ^ n) ⊗ₜ[k] 1 * 1 ⊗ₜ[k] (y ^ q ^ n)
⊢ x ⊗ₜ[k] y ^ q ^ n ∈ (algebraMap R (R ⊗[k] K)).range

Tactic:
Algebra.TensorProduct.tmul_pow,

Goal state after:
case h
k : Type u_1
K : Type u_2
R : Type u_3
inst✝⁶ : Field k
inst✝⁵ : Field K
inst✝⁴ : Algebra k K
inst✝³ : CommRing R
inst✝² : Algebra k R
inst✝¹ : IsPurelyInseparable k K
q : ℕ
inst✝ : ExpChar k q
a✝ : Nontrivial (R ⊗[k] K)
hq : Nat.Prime q
x : R
y : K
n : ℕ
a : k
ha : (algebraMap k K) a = y ^ q ^ n
this : (x ^ q ^ n) ⊗ₜ[k] (y ^ q ^ n) = (x ^ q ^ n) ⊗ₜ[k] 1 * 1 ⊗ₜ[k] (y ^ q ^ n)
⊢ (x ^ q ^ n) ⊗ₜ[k] (y ^ q ^ n) ∈ (algebraMap R (R ⊗[k] K)).range
Module: Mathlib.RingTheory.IsGaloisGroup.Defs

Goal state before:
pp: G : Type u_1
A : Type u_2
B : Type u_4
inst✝⁶ : Group G
inst✝⁵ : CommSemiring A
inst✝⁴ : Semiring B
inst✝³ : Algebra A B
inst✝² : MulSemiringAction G B
hG : IsGaloisGroup G A B
H : Type u_5
inst✝¹ : Group H
inst✝ : MulSemiringAction H B
e : H ≃* G
he : ∀ (h : H) (x : B), e h • x = h • x
m₁✝ m₂✝ : H
h : ∀ (a : B), m₁✝ • a = m₂✝ • a
⊢ ∀ (a : B), e m₁✝ • a = e m₂✝ • a

Tactic:
by simpa only [he]

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

Goal state before:
pp: G : Type u_1
inst✝¹¹ : Group G
H : Subgroup G
A : Type u_2
B : Type u_3
C : Type u_4
inst✝¹⁰ : CommSemiring A
inst✝⁹ : Semiring C
inst✝⁸ : Algebra A C
inst✝⁷ : MulSemiringAction G C
N : Subgroup G
inst✝⁶ : CommSemiring B
inst✝⁵ : Algebra B C
inst✝⁴ : FaithfulSMul B C
inst✝³ : MulSemiringAction G B
inst✝² : SMulDistribClass G B C
inst✝¹ : IsGaloisGroup (↥N) B C
inst✝ : N.Normal
this : MulSemiringAction (G ⧸ N) B := mulSemiringActionQuotient G B C N
g : G
q : G ⧸ N
b : B
h : G
⊢ (g • Quotient.mk'' h) • b = g • Quotient.mk'' h • b

Tactic:
by
    simp [mul_smul, mulSemiringActionQuotient_smul_def]

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

Goal state before:
pp: case pos
K : Type u_4
L : Type u_5
inst✝² : Field K
inst✝¹ : Field L
inst✝ : Algebra K L
H : ¬Algebra.IsSeparable K L
p : ℕ
hp : ExpChar K p
this : p ≠ 0
h₀ : FiniteDimensional K L
x : ↥(separableClosure K L)
⊢ (trace K ↥(separableClosure K L)) ((trace (↥(separableClosure K L)) L) ((algebraMap (↥(separableClosure K L)) L) x)) =
    0 ((algebraMap (↥(separableClosure K L)) L) x)

Tactic:
trace_algebraMap

Goal state after:
case pos
K : Type u_4
L : Type u_5
inst✝² : Field K
inst✝¹ : Field L
inst✝ : Algebra K L
H : ¬Algebra.IsSeparable K L
p : ℕ
hp : ExpChar K p
this : p ≠ 0
h₀ : FiniteDimensional K L
x : ↥(separableClosure K L)
⊢ (trace K ↥(separableClosure K L)) (finrank (↥(separableClosure K L)) L • x) =
    0 ((algebraMap (↥(separableClosure K L)) L) x)
Module: Mathlib.RingTheory.Trace.Basic

Goal state before:
pp: ι : Type w
A : Type u
B : Type v
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Fintype ι
b : Basis ι A B
z : B
i : ι
⊢ ∑ j, traceMatrix A (⇑b) i j * replicateCol (Fin 1) (b.equivFun z) j 0 = (trace A B) (z * b i)

Tactic:
traceMatrix

Goal state after:
ι : Type w
A : Type u
B : Type v
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Fintype ι
b : Basis ι A B
z : B
i : ι
⊢ ∑ j, of (fun i j ↦ ((traceForm A B) (b i)) (b j)) i j * replicateCol (Fin 1) (b.equivFun z) j 0 =
    (trace A B) (z * b i)
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: 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
hu : orderOf u = p
⊢ u = 1

Tactic:
← sub_left_inj,

Goal state after:
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
hu : orderOf u = p
⊢ u - ?m.139 = 1 - ?m.139

K : Type u_1
inst✝³ : Ring K
inst✝² : NoZeroDivisors K
inst✝¹ : Nontrivial K
G : Subgroup Kˣ
inst✝ : Fintype ↥G
n : ℕ := ⋯
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 := ⋯
hu : orderOf u = p
⊢ K
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝³ : Ring K
inst✝² : NoZeroDivisors K
inst✝¹ : Nontrivial K
G : Subgroup Kˣ
inst✝ : Fintype ↥G
n : ℕ := ⋯
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 := ⋯
hu : orderOf u = p
⊢ (u - 1) ^ p = 0

Tactic:
sub_pow_char_of_commute,

Goal state after:
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
hu : orderOf u = p
⊢ u ^ p - 1 ^ p = 0

case h
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
hu : orderOf u = p
⊢ Commute u 1
Module: Mathlib.LinearAlgebra.Quotient.Pi

Goal state before:
pp: ι : Type u_1
R : Type u_2
inst✝⁶ : CommRing R
Ms : ι → Type u_3
inst✝⁵ : (i : ι) → AddCommGroup (Ms i)
inst✝⁴ : (i : ι) → Module R (Ms i)
N : Type u_4
inst✝³ : AddCommGroup N
inst✝² : Module R N
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
p : (i : ι) → Submodule R (Ms i)
q : Submodule R N
f : (i : ι) → Ms i →ₗ[R] N
hf : ∀ (i : ι), p i ≤ comap (f i) q
i : ι
x : Ms i ⧸ p i
⊢ ∑ x_1, ((p x_1).mapQ q (f x_1) ⋯) (Pi.single i x x_1) = ((p i).mapQ q (f i) ⋯) x

Tactic:
Finset.sum_eq_single i

Goal state after:
ι : Type u_1
R : Type u_2
inst✝⁶ : CommRing R
Ms : ι → Type u_3
inst✝⁵ : (i : ι) → AddCommGroup (Ms i)
inst✝⁴ : (i : ι) → Module R (Ms i)
N : Type u_4
inst✝³ : AddCommGroup N
inst✝² : Module R N
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
p : (i : ι) → Submodule R (Ms i)
q : Submodule R N
f : (i : ι) → Ms i →ₗ[R] N
hf : ∀ (i : ι), p i ≤ comap (f i) q
i : ι
x : Ms i ⧸ p i
⊢ ((p i).mapQ q (f i) ⋯) (Pi.single i x i) = ((p i).mapQ q (f i) ⋯) x

case h₀
ι : Type u_1
R : Type u_2
inst✝⁶ : CommRing R
Ms : ι → Type u_3
inst✝⁵ : (i : ι) → AddCommGroup (Ms i)
inst✝⁴ : (i : ι) → Module R (Ms i)
N : Type u_4
inst✝³ : AddCommGroup N
inst✝² : Module R N
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
p : (i : ι) → Submodule R (Ms i)
q : Submodule R N
f : (i : ι) → Ms i →ₗ[R] N
hf : ∀ (i : ι), p i ≤ comap (f i) q
i : ι
x : Ms i ⧸ p i
⊢ ∀ b ∈ Finset.univ, b ≠ i → ((p b).mapQ q (f b) ⋯) (Pi.single i x b) = 0

case h₁
ι : Type u_1
R : Type u_2
inst✝⁶ : CommRing R
Ms : ι → Type u_3
inst✝⁵ : (i : ι) → AddCommGroup (Ms i)
inst✝⁴ : (i : ι) → Module R (Ms i)
N : Type u_4
inst✝³ : AddCommGroup N
inst✝² : Module R N
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
p : (i : ι) → Submodule R (Ms i)
q : Submodule R N
f : (i : ι) → Ms i →ₗ[R] N
hf : ∀ (i : ι), p i ≤ comap (f i) q
i : ι
x : Ms i ⧸ p i
⊢ i ∉ Finset.univ → ((p i).mapQ q (f i) ⋯) (Pi.single i x i) = 0
Module: Mathlib.RingTheory.Invariant.Basic

Goal state before:
pp: case intro
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k →ₐ[A ⧸ P] k
f : B ⧸ Q →ₐ[A ⧸ P] k := IsScalarTower.toAlgHom (A ⧸ P) (B ⧸ Q) k
hf : Function.Injective ⇑f
x : B
val✝ : Fintype G
algInst✝¹ : Algebra A k := ((algebraMap (A ⧸ P) k).comp (algebraMap A (A ⧸ P))).toAlgebra
algInst✝ : Algebra B k := ((algebraMap (B ⧸ Q) k).comp (algebraMap B (B ⧸ Q))).toAlgebra
scalarTowerInst✝¹ : IsScalarTower A (A ⧸ P) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap A k))
scalarTowerInst✝ : IsScalarTower B (B ⧸ Q) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap B k))
⊢ (σ.comp f).toRingHom ((mk Q) x) ∈ f.range

Tactic:
have : IsScalarTower A (B ⧸ Q) k := .of_algebraMap_eq fun x ↦
    (IsScalarTower.algebraMap_apply (A ⧸ P) (B ⧸ Q) k (mk P x))

Goal state after:
case intro
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k →ₐ[A ⧸ P] k
f : B ⧸ Q →ₐ[A ⧸ P] k := IsScalarTower.toAlgHom (A ⧸ P) (B ⧸ Q) k
hf : Function.Injective ⇑f
x : B
val✝ : Fintype G
algInst✝¹ : Algebra A k := ((algebraMap (A ⧸ P) k).comp (algebraMap A (A ⧸ P))).toAlgebra
algInst✝ : Algebra B k := ((algebraMap (B ⧸ Q) k).comp (algebraMap B (B ⧸ Q))).toAlgebra
scalarTowerInst✝¹ : IsScalarTower A (A ⧸ P) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap A k))
scalarTowerInst✝ : IsScalarTower B (B ⧸ Q) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap B k))
this : IsScalarTower A (B ⧸ Q) k
⊢ (σ.comp f).toRingHom ((mk Q) x) ∈ f.range
Module: Mathlib.RingTheory.UniqueFactorizationDomain.Multiplicative

Goal state before:
pp: α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
inst✝ : DecidableEq α
s : Finset α
i : α → ℕ
p : α
hps : p ∉ s
is_prime : ∀ q ∈ insert p s, Prime q
is_coprime : ∀ q ∈ insert p s, ∀ q' ∈ insert p s, q ∣ q' → q = q'
hp : Prime p
d : α
hdprod : d ∣ ∏ p' ∈ s, p' ^ i p'
hd : Prime d
hdp : d ∣ p
q : α
q_mem : q ∈ s.val
q_mem' : q ^ i q ∈ Multiset.map (fun p' ↦ p' ^ i p') s.val
hdq : d ∣ q
this : p ∣ q
⊢ p ∈ s ↔ q ∈ s.val

Tactic:
Finset.mem_val,

Goal state after:
α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
inst✝ : DecidableEq α
s : Finset α
i : α → ℕ
p : α
hps : p ∉ s
is_prime : ∀ q ∈ insert p s, Prime q
is_coprime : ∀ q ∈ insert p s, ∀ q' ∈ insert p s, q ∣ q' → q = q'
hp : Prime p
d : α
hdprod : d ∣ ∏ p' ∈ s, p' ^ i p'
hd : Prime d
hdp : d ∣ p
q : α
q_mem : q ∈ s.val
q_mem' : q ^ i q ∈ Multiset.map (fun p' ↦ p' ^ i p') s.val
hdq : d ∣ q
this : p ∣ q
⊢ p ∈ s ↔ q ∈ s
Module: Mathlib.RingTheory.UniqueFactorizationDomain.Multiplicative

Goal state before:
pp: case insert
α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
β : Type u_3
inst✝ : CommMonoidWithZero β
f : α → β
i j : α → ℕ
h1 : ∀ {x y : α}, IsUnit y → f (x * y) = f x * f y
hpr : ∀ {p : α} (i : ℕ), Prime p → f (p ^ i) = f p ^ i
hcp : ∀ {x y : α}, IsRelPrime x y → f (x * y) = f x * f y
this : DecidableEq α := Classical.decEq α
p : α
s : Finset α
hps : p ∉ s
ih :
  (∀ p ∈ s, Prime p) →
    (∀ p ∈ s, ∀ q ∈ s, p ∣ q → p = q) → f (∏ p ∈ s, p ^ (i p + j p)) = f (∏ p ∈ s, p ^ i p) * f (∏ p ∈ s, p ^ j p)
is_prime : ∀ p_1 ∈ insert p s, Prime p_1
is_coprime : ∀ p_1 ∈ insert p s, ∀ q ∈ insert p s, p_1 ∣ q → p_1 = q
hpr_p : Prime p
hpr_s : ∀ p ∈ s, Prime p
hcp_p : ∀ (i : α → ℕ), IsRelPrime (p ^ i p) (∏ p' ∈ s, p' ^ i p')
hcp_s : ∀ p ∈ s, ∀ q ∈ s, p ∣ q → p = q
⊢ f p ^ (i p + j p) * f (∏ p' ∈ s, p' ^ (i p' + j p')) =
    f p ^ i p * f (∏ p' ∈ s, p' ^ i p') * (f p ^ j p * f (∏ p' ∈ s, p' ^ j p'))

Tactic:
ih hpr_s hcp_s,

Goal state after:
case insert
α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
β : Type u_3
inst✝ : CommMonoidWithZero β
f : α → β
i j : α → ℕ
h1 : ∀ {x y : α}, IsUnit y → f (x * y) = f x * f y
hpr : ∀ {p : α} (i : ℕ), Prime p → f (p ^ i) = f p ^ i
hcp : ∀ {x y : α}, IsRelPrime x y → f (x * y) = f x * f y
this : DecidableEq α := Classical.decEq α
p : α
s : Finset α
hps : p ∉ s
ih :
  (∀ p ∈ s, Prime p) →
    (∀ p ∈ s, ∀ q ∈ s, p ∣ q → p = q) → f (∏ p ∈ s, p ^ (i p + j p)) = f (∏ p ∈ s, p ^ i p) * f (∏ p ∈ s, p ^ j p)
is_prime : ∀ p_1 ∈ insert p s, Prime p_1
is_coprime : ∀ p_1 ∈ insert p s, ∀ q ∈ insert p s, p_1 ∣ q → p_1 = q
hpr_p : Prime p
hpr_s : ∀ p ∈ s, Prime p
hcp_p : ∀ (i : α → ℕ), IsRelPrime (p ^ i p) (∏ p' ∈ s, p' ^ i p')
hcp_s : ∀ p ∈ s, ∀ q ∈ s, p ∣ q → p = q
⊢ f p ^ (i p + j p) * (f (∏ p ∈ s, p ^ i p) * f (∏ p ∈ s, p ^ j p)) =
    f p ^ i p * f (∏ p' ∈ s, p' ^ i p') * (f p ^ j p * f (∏ p' ∈ s, p' ^ j p'))
Module: Mathlib.RingTheory.UniqueFactorizationDomain.Multiplicative

Goal state before:
pp: α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
β : Type u_3
inst✝ : CommMonoidWithZero β
f : α → β
a b : α
h0 : f 0 = 0
h1 : ∀ {x y : α}, IsUnit y → f (x * y) = f x * f y
hpr : ∀ {p : α} (i : ℕ), Prime p → f (p ^ i) = f p ^ i
hcp : ∀ {x y : α}, IsRelPrime x y → f (x * y) = f x * f y
this : DecidableEq α := Classical.decEq α
ha0 : ¬a = 0
hb0 : ¬b = 0
hf1 : f 1 = 0
⊢ f (a * b * 1) = 0

Tactic:
simp only [h1 isUnit_one, hf1, mul_zero]

Goal state after:
Module: Mathlib.RingTheory.UniqueFactorizationDomain.Multiplicative

Goal state before:
pp: α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
β : Type u_3
inst✝ : CommMonoidWithZero β
f : α → β
a b : α
h0 : f 0 = 0
h1 : ∀ {x y : α}, IsUnit y → f (x * y) = f x * f y
hpr : ∀ {p : α} (i : ℕ), Prime p → f (p ^ i) = f p ^ i
hcp : ∀ {x y : α}, IsRelPrime x y → f (x * y) = f x * f y
this : DecidableEq α := Classical.decEq α
ha0 : ¬a = 0
hb0 : ¬b = 0
hf1 : f 1 = 0
⊢ 0 = f a * f (b * 1)

Tactic:
simp only [h1 isUnit_one, hf1, mul_zero]

Goal state after:
Module: Mathlib.RingTheory.Finiteness.NilpotentKer

Goal state before:
pp: case zero
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Module.Finite R T
f : S →ₐ[R] T
hf₁ : Function.Surjective ⇑f
I : Ideal S
hI : RingHom.ker f = I
hf₂ : I ≤ nilradical S
hf₃ : I.FG
this : Module.Finite R (S ⧸ I)
⊢ Module.Finite R (S ⧸ I ^ 0)

Tactic:
rw [pow_zero, Ideal.one_eq_top]; infer_instance

Goal state after: