mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Measure.Decomposition.RadonNikodym

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : μ.HaveLebesgueDecomposition ν
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
⊢ μ.rnDeriv ν ≤ᵐ[ν] 1 ↔ μ ≤ ν

Tactic:
by
  refine ⟨fun h s ↦ ?_, fun h ↦ rnDeriv_le_one_of_le h⟩
  rw [← withDensity_rnDeriv_eq _ _ hμν, withDensity_apply', ← setLIntegral_one]
  exact setLIntegral_mono_ae aemeasurable_const (h.mono fun _ hh _ ↦ hh)

Goal state after:
Module: Mathlib.Dynamics.Transitive

Goal state before:
pp: case refine_2
M : Type u_1
α : Type u_2
inst✝² : TopologicalSpace α
inst✝¹ : Monoid M
inst✝ : MulAction M α
h : ContinuousConstSMul M α
h₄ : ∀ {U : Set α}, IsOpen U → U.Nonempty → (∀ (m : M), (fun x ↦ m • x) ⁻¹' U ⊆ U) → Dense U
U✝ : Set α
hU : IsOpen U✝
x✝¹ : U✝.Nonempty
b : M
x✝ : α
⊢ ∀ (x : M), (x * b) • x✝ ∈ U✝ → ∃ i, i • x✝ ∈ U✝

Tactic:
exact fun c hc ↦ ⟨c * b, hc⟩

Goal state after:
Module: Mathlib.FieldTheory.AbelRuffini

Goal state before:
pp: case pos
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : n = 0
⊢ Group.IsSolvable (C 1 - C a).Gal

Tactic:
← C_sub

Goal state after:
case pos
F : Type u_1
inst✝ : Field F
n : ℕ
a : F
h : (map (RingHom.id F) (X ^ n - 1)).Splits
ha : ¬a = 0
ha' : (algebraMap F (X ^ n - C a).SplittingField) a ≠ 0
hn : n = 0
⊢ Group.IsSolvable (C (1 - a)).Gal
Module: Mathlib.FieldTheory.IsAlgClosed.Classification

Goal state before:
pp: K : Type u
L : Type v
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : IsAlgClosed K
inst✝² : IsAlgClosed L
inst✝¹ : CharZero K
inst✝ : CharZero L
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
s : Set K
hs : IsTranscendenceBasis ℤ Subtype.val
t : Set L
ht : IsTranscendenceBasis ℤ Subtype.val
⊢ Nonempty (K ≃+* L)

Tactic:
have hL : ℵ₀ < #L := by
    rwa [← aleph0_lt_lift.{v, u}, ← lift_mk_eq'.2 hKL, aleph0_lt_lift]

Goal state after:
K : Type u
L : Type v
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : IsAlgClosed K
inst✝² : IsAlgClosed L
inst✝¹ : CharZero K
inst✝ : CharZero L
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
s : Set K
hs : IsTranscendenceBasis ℤ Subtype.val
t : Set L
ht : IsTranscendenceBasis ℤ Subtype.val
hL : ℵ₀ < #L
⊢ Nonempty (K ≃+* L)
Module: Mathlib.FieldTheory.IsAlgClosed.Classification

Goal state before:
pp: K : Type u
L : Type v
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : IsAlgClosed K
inst✝² : IsAlgClosed L
inst✝¹ : CharZero K
inst✝ : CharZero L
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
s : Set K
hs : IsTranscendenceBasis ℤ Subtype.val
t : Set L
ht : IsTranscendenceBasis ℤ Subtype.val
hL : ℵ₀ < #L
⊢ Cardinal.lift.{v, u} #↑s = Cardinal.lift.{u, v} #↑t

Tactic:
← lift_injective (cardinal_eq_cardinal_transcendence_basis_of_aleph0_lt _
        hs (le_of_eq mk_int) hK),

Goal state after:
K : Type u
L : Type v
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : IsAlgClosed K
inst✝² : IsAlgClosed L
inst✝¹ : CharZero K
inst✝ : CharZero L
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
s : Set K
hs : IsTranscendenceBasis ℤ Subtype.val
t : Set L
ht : IsTranscendenceBasis ℤ Subtype.val
hL : ℵ₀ < #L
⊢ Cardinal.lift.{v, u} #K = Cardinal.lift.{u, v} #↑t
Module: Mathlib.FieldTheory.IsAlgClosed.Classification

Goal state before:
pp: K : Type u
L : Type v
inst✝⁶ : Field K
inst✝⁵ : Field L
inst✝⁴ : IsAlgClosed K
inst✝³ : IsAlgClosed L
p : ℕ
inst✝² : Fact (Nat.Prime p)
inst✝¹ : CharP K p
inst✝ : CharP L p
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
this✝ : Algebra (ZMod p) K := ZMod.algebra K p
this : Algebra (ZMod p) L := ZMod.algebra L p
s : Set K
hs : IsTranscendenceBasis (ZMod p) Subtype.val
t : Set L
ht : IsTranscendenceBasis (ZMod p) Subtype.val
⊢ Nonempty (K ≃+* L)

Tactic:
have hL : ℵ₀ < #L := by
    rwa [← aleph0_lt_lift.{v, u}, ← lift_mk_eq'.2 hKL, aleph0_lt_lift]

Goal state after:
K : Type u
L : Type v
inst✝⁶ : Field K
inst✝⁵ : Field L
inst✝⁴ : IsAlgClosed K
inst✝³ : IsAlgClosed L
p : ℕ
inst✝² : Fact (Nat.Prime p)
inst✝¹ : CharP K p
inst✝ : CharP L p
hK : ℵ₀ < #K
hKL : Nonempty (K ≃ L)
this✝ : Algebra (ZMod p) K := ZMod.algebra K p
this : Algebra (ZMod p) L := ZMod.algebra L p
s : Set K
hs : IsTranscendenceBasis (ZMod p) Subtype.val
t : Set L
ht : IsTranscendenceBasis (ZMod p) Subtype.val
hL : ℵ₀ < #L
⊢ Nonempty (K ≃+* L)
Module: Mathlib.FieldTheory.AbelRuffini

Goal state before:
pp: case h
F : Type u_3
inst✝¹ : Field F
E : Type u_4
inst✝ : Field E
i : F →+* E
n : ℕ
a : F
ha : a ≠ 0
h : (map i (X ^ n - C a)).Splits
ha' : i a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : (X ^ n - C a).degree ≠ 0
b : E
hb : b ^ n = i a
hb' : b ≠ 0
s : Multiset E := (map i (X ^ n - C a)).roots
hs : map i (X ^ n - C a) = (Multiset.map (fun x ↦ X - C x) s).prod
hs' : s.card = n
C_mul_C : C (i a⁻¹) * C (i a) = 1
key1 : map i (X ^ n - 1) = C (i a⁻¹) * (map i (X ^ n - C a)).comp (C b * X)
⊢ map i (X ^ n - 1) = (Multiset.map ((fun x ↦ X - C x) ∘ fun c ↦ c / b) s).prod

Tactic:
have key2 : ((fun q : E[X] => q.comp (C b * X)) ∘ fun c : E => X - C c) = fun c : E =>
      C b * (X - C (c / b)) := by
    ext1 c
    dsimp only [Function.comp_apply]
    rw [sub_comp, X_comp, C_comp, mul_sub, ← C_mul, mul_div_cancel₀ c hb']

Goal state after:
case h
F : Type u_3
inst✝¹ : Field F
E : Type u_4
inst✝ : Field E
i : F →+* E
n : ℕ
a : F
ha : a ≠ 0
h : (map i (X ^ n - C a)).Splits
ha' : i a ≠ 0
hn : ¬n = 0
hn' : 0 < n
hn'' : (X ^ n - C a).degree ≠ 0
b : E
hb : b ^ n = i a
hb' : b ≠ 0
s : Multiset E := (map i (X ^ n - C a)).roots
hs : map i (X ^ n - C a) = (Multiset.map (fun x ↦ X - C x) s).prod
hs' : s.card = n
C_mul_C : C (i a⁻¹) * C (i a) = 1
key1 : map i (X ^ n - 1) = C (i a⁻¹) * (map i (X ^ n - C a)).comp (C b * X)
key2 : ((fun q ↦ q.comp (C b * X)) ∘ fun c ↦ X - C c) = fun c ↦ C b * (X - C (c / b))
⊢ map i (X ^ n - 1) = (Multiset.map ((fun x ↦ X - C x) ∘ fun c ↦ c / b) s).prod
Module: Mathlib.ModelTheory.Algebra.Ring.Basic

Goal state before:
pp: α : Type u_1
⊢ (↑[Sum.inl ⟨2, add⟩, Sum.inl ⟨2, mul⟩, Sum.inl ⟨1, neg⟩, Sum.inl ⟨0, zero⟩, Sum.inl ⟨0, one⟩]).Nodup

Tactic:
dsimp [Language.Symbols]

Goal state after:
α : Type u_1
⊢ (↑[Sum.inl ⟨2, add⟩, Sum.inl ⟨2, mul⟩, Sum.inl ⟨1, neg⟩, Sum.inl ⟨0, zero⟩, Sum.inl ⟨0, one⟩]).Nodup
Module: Mathlib.ModelTheory.Algebra.Ring.Basic

Goal state before:
pp: α : Type u_1
x : ring.Symbols
⊢ x ∈
    { val := ↑[Sum.inl ⟨2, add⟩, Sum.inl ⟨2, mul⟩, Sum.inl ⟨1, neg⟩, Sum.inl ⟨0, zero⟩, Sum.inl ⟨0, one⟩],
      nodup := instFintypeSymbolsRing._proof_1 }

Tactic:
dsimp [Language.Symbols]

Goal state after:
α : Type u_1
x : ring.Symbols
⊢ x ∈
    { val := ↑[Sum.inl ⟨2, add⟩, Sum.inl ⟨2, mul⟩, Sum.inl ⟨1, neg⟩, Sum.inl ⟨0, zero⟩, Sum.inl ⟨0, one⟩],
      nodup := instFintypeSymbolsRing._proof_1 }
Module: Mathlib.ModelTheory.Algebra.Field.CharP

Goal state before:
pp: case pos
p : ℕ
K : Type u_1
inst✝¹ : Field K
inst✝ : CompatibleRing K
hp0 : ¬p = 0
hp : Nat.Prime p
⊢ K ⊨ {eqZero p} ↔ CharP K p

pp: case neg
p : ℕ
K : Type u_1
inst✝¹ : Field K
inst✝ : CompatibleRing K
hp0 : ¬p = 0
hp : ¬Nat.Prime p
⊢ K ⊨ {⊥} ↔ CharP K p

Tactic:
· simp only [Theory.model_iff, Set.mem_singleton_iff, Sentence.Realize, forall_eq,
      realize_eqZero, ← CharP.charP_iff_prime_eq_zero hp]

Goal state after:
case neg
p : ℕ
K : Type u_1
inst✝¹ : Field K
inst✝ : CompatibleRing K
hp0 : ¬p = 0
hp : ¬Nat.Prime p
⊢ K ⊨ {⊥} ↔ CharP K p
Module: Mathlib.ModelTheory.Ultraproducts

Goal state before:
pp: case rel
α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
x : β → (a : α) → M a
n✝ l✝ : ℕ
R✝ : L.Relations l✝
ts✝ : Fin l✝ → L.Term (β ⊕ Fin n✝)
v : Fin n✝ → (a : α) → M a
⊢ ((BoundedFormula.rel R✝ ts✝).Realize (fun i ↦ Quotient.mk' (x i)) fun i ↦ Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, (BoundedFormula.rel R✝ ts✝).Realize (fun i ↦ x i a) fun i ↦ v i a

Tactic:
have h2 : ∀ a : α, (Sum.elim (fun i : β => x i a) fun i => v i a) = fun i => Sum.elim x v i a :=
      fun a => funext fun i => Sum.casesOn i (fun i => rfl) fun i => rfl
    simp only [BoundedFormula.Realize, h2]
    erw [(Sum.comp_elim ((↑) : (∀ a, M a) → (u : Filter α).Product M) x v).symm]
    conv_lhs => enter [2, i]; erw [term_realize_cast]
    apply relMap_quotient_mk'

Goal state after:
Module: Mathlib.ModelTheory.ElementaryMaps

Goal state before:
pp: L : Language
M : Type u_1
N : Type u_2
inst✝¹ : L.Structure M
inst✝ : L.Structure N
φ : M ↪ₑ[L] N
n : ℕ
f : L.Functions n
x : Fin n → M
h : (Formula.graph f).Realize (⇑φ ∘ Fin.cons (funMap f x) x) ↔ (Formula.graph f).Realize (Fin.cons (funMap f x) x)
⊢ φ (funMap f x) = funMap f (⇑φ ∘ x)

Tactic:
Formula.realize_graph,

Goal state after:
L : Language
M : Type u_1
N : Type u_2
inst✝¹ : L.Structure M
inst✝ : L.Structure N
φ : M ↪ₑ[L] N
n : ℕ
f : L.Functions n
x : Fin n → M
h : (Formula.graph f).Realize (⇑φ ∘ Fin.cons (funMap f x) x) ↔ funMap f x = funMap f x
⊢ φ (funMap f x) = funMap f (⇑φ ∘ x)
Module: Mathlib.ModelTheory.Encoding

Goal state before:
pp: case equal
L : Language
α : Type u'
l✝ : List ((n : ℕ) × L.BoundedFormula α n)
n n✝ : ℕ
t₁✝ t₂✝ : L.Term (α ⊕ Fin n✝)
l : List ((k : ℕ) × L.Term (α ⊕ Fin k) ⊕ (n : ℕ) × L.Relations n ⊕ ℕ)
⊢ ⟨⟨n✝, equal t₁✝ t₂✝⟩.fst, equal t₁✝ (⋯.mp t₂✝)⟩ :: listDecode ([] ++ l) = ⟨n✝, equal t₁✝ t₂✝⟩ :: listDecode l

pp: case equal.hc
L : Language
α : Type u'
l✝ : List ((n : ℕ) × L.BoundedFormula α n)
n n✝ : ℕ
t₁✝ t₂✝ : L.Term (α ⊕ Fin n✝)
l : List ((k : ℕ) × L.Term (α ⊕ Fin k) ⊕ (n : ℕ) × L.Relations n ⊕ ℕ)
⊢ ⟨n✝, equal t₁✝ t₂✝⟩.fst = ⟨n✝, equal t₁✝ t₂✝⟩.fst

Tactic:
· simp only [eq_mp_eq_cast, cast_eq, nil_append]

Goal state after:
case equal.hc
L : Language
α : Type u'
l✝ : List ((n : ℕ) × L.BoundedFormula α n)
n n✝ : ℕ
t₁✝ t₂✝ : L.Term (α ⊕ Fin n✝)
l : List ((k : ℕ) × L.Term (α ⊕ Fin k) ⊕ (n : ℕ) × L.Relations n ⊕ ℕ)
⊢ ⟨n✝, equal t₁✝ t₂✝⟩.fst = ⟨n✝, equal t₁✝ t₂✝⟩.fst
Module: Mathlib.ModelTheory.Semantics

Goal state before:
pp: L : Language
M : Type w
N : Type u_1
inst✝² : L.Structure M
inst✝¹ : L.Structure N
inst✝ : N ⊨ L.completeTheory M
φ : L.Sentence
h : ¬M ⊨ φ
⊢ ¬N ⊨ φ

Tactic:
← Sentence.realize_not

Goal state after:
L : Language
M : Type w
N : Type u_1
inst✝² : L.Structure M
inst✝¹ : L.Structure N
inst✝ : N ⊨ L.completeTheory M
φ : L.Sentence
h : M ⊨ Formula.not φ
⊢ N ⊨ Formula.not φ
Module: Mathlib.ModelTheory.Semantics

Goal state before:
pp: case mpr
L : Language
M : Type w
inst✝² : L.Structure M
α : Type u'
inst✝¹ : DecidableEq α
inst✝ : Nonempty M
φ : L.Formula α
h : M ⊨ φ.exClosure
⊢ ∃ v, M ⊨ equivSentence φ

Tactic:
obtain ⟨v, hv⟩ := (Formula.realize_exClosure φ).1 h

Goal state after:
case mpr
L : Language
M : Type w
inst✝² : L.Structure M
α : Type u'
inst✝¹ : DecidableEq α
inst✝ : Nonempty M
φ : L.Formula α
h : M ⊨ φ.exClosure
v : ↥(BoundedFormula.freeVarFinset φ) → M
hv : Realize (BoundedFormula.restrictFreeVar φ id) v
⊢ ∃ v, M ⊨ equivSentence φ
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
T : L.Theory
h : T.IsFinitelySatisfiable
M : Finset ↑T → Type (max u v) := fun T0 ↦ ↑(Nonempty.some ⋯)
M' : Type (max u v) := (↑(Ultrafilter.of Filter.atTop)).Product M
φ : L.Sentence
hφ : φ ∈ T
⊢ M' ⊨ φ

Tactic:
Ultraproduct.sentence_realize

Goal state after:
L : Language
T : L.Theory
h : T.IsFinitelySatisfiable
M : Finset ↑T → Type (max u v) := fun T0 ↦ ↑(Nonempty.some ⋯)
M' : Type (max u v) := (↑(Ultrafilter.of Filter.atTop)).Product M
φ : L.Sentence
hφ : φ ∈ T
⊢ ∀ᶠ (a : Finset ↑T) in ↑(Ultrafilter.of Filter.atTop), M a ⊨ φ
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
T : L.Theory
φ : L.Sentence
M : T.ModelType
h : ¬↑M ⊨ φ
⊢ Nonempty (T ∪ {Formula.not φ}).ModelType

Tactic:
← Sentence.realize_not

Goal state after:
L : Language
T : L.Theory
φ : L.Sentence
M : T.ModelType
h : ↑M ⊨ Formula.not φ
⊢ Nonempty (T ∪ {Formula.not φ}).ModelType
Module: Mathlib.RingTheory.Nullstellensatz

Goal state before:
pp: k : Type u_1
K : Type u_2
inst✝⁴ : Field k
inst✝³ : Field K
inst✝² : Algebra k K
σ : Type u_3
inst✝¹ : IsAlgClosed K
inst✝ : Finite σ
I : Ideal (MvPolynomial σ k)
hI : I.IsMaximal
this : Field (MvPolynomial σ k ⧸ I) := Quotient.field I
⊢ Algebra.IsIntegral k (MvPolynomial σ k ⧸ I)

Tactic:
← algebraMap_isIntegral_iff

Goal state after:
k : Type u_1
K : Type u_2
inst✝⁴ : Field k
inst✝³ : Field K
inst✝² : Algebra k K
σ : Type u_3
inst✝¹ : IsAlgClosed K
inst✝ : Finite σ
I : Ideal (MvPolynomial σ k)
hI : I.IsMaximal
this : Field (MvPolynomial σ k ⧸ I) := Quotient.field I
⊢ (algebraMap k (MvPolynomial σ k ⧸ I)).IsIntegral
Module: Mathlib.FieldTheory.AxGrothendieck

Goal state before:
pp: ι : Type u_1
K : Type u_2
R : Type u_3
inst✝⁴ : Field K
inst✝³ : Finite K
inst✝² : CommRing R
inst✝¹ : Finite ι
inst✝ : Algebra K R
alg : Algebra.IsAlgebraic K R
ps : ι → MvPolynomial ι R
S : Set (ι → R)
hm : Set.MapsTo (fun v i ↦ (eval v) (ps i)) S S
hinj : Set.InjOn (fun v i ↦ (eval v) (ps i)) S
is_int : ∀ (x : R), IsIntegral K x
v : ι → R
hvS : v ∈ S
val✝ : Fintype ι
s : Finset R := (univ.biUnion fun i ↦ image (fun x ↦ coeff x (ps i)) (ps i).support) ∪ image v univ
hv : ∀ (i : ι), v i ∈ Algebra.adjoin K ↑s
hs₁ : ∀ (i : ι), ∀ k ∈ (ps i).support, coeff k (ps i) ∈ Algebra.adjoin K ↑s
this✝ : IsNoetherian K ↥(Algebra.adjoin K ↑s)
this : Finite ↥(Algebra.adjoin K ↑s)
S' : Set (ι → ↥(Algebra.adjoin K ↑s)) := (fun v ↦ Subtype.val ∘ v) ⁻¹' S
res : ↑S' → ↑S' := fun x ↦ ⟨fun i ↦ ⟨(eval fun j ↦ ↑(↑x j)) (ps i), ⋯⟩, ⋯⟩
x y : ↑S'
i : ι
hxy : ∀ (x_1 : ι), ↑(↑(res x) x_1) = ↑(↑(res y) x_1)
⊢ ↑(↑x i) = ↑(↑y i)

Tactic:
exact congr_fun (hinj x.2 y.2 (funext hxy)) i

Goal state after:
Module: Mathlib.SetTheory.Cardinal.Divisibility

Goal state before:
pp: case refine_2.inl
a : Cardinal.{u}
ha : ℵ₀ ≤ a
b c : Cardinal.{u}
hbc : a ∣ b * c
hz : b * c = 0
⊢ a ∣ b ∨ a ∣ c

Tactic:
rcases mul_eq_zero.mp hz with (rfl | rfl) <;> simp

Goal state after:
Module: Mathlib.FieldTheory.CardinalEmb

Goal state before:
pp: F : Type u
E : Type v
inst✝³ : Field F
inst✝² : Field E
inst✝¹ : Algebra F E
rank_inf : Fact (ℵ₀ ≤ Module.rank F E)
inst✝ : Algebra.IsAlgebraic F E
i : (Module.rank F E).ord.ToType
ih : (y : (Module.rank F E).ord.ToType) → y < i → (Module.rank F E).ord.ToType
s : Set E := failed to pretty print expression (use 'set_option pp.rawOnError true' for raw representation)
this✝ : failed to pretty print expression (use 'set_option pp.rawOnError true' for raw representation)
this : failed to pretty print expression (use 'set_option pp.rawOnError true' for raw representation)
⊢ False

Tactic:
adjoin_basis_eq_top,

Goal state after:
F : Type u
E : Type v
inst✝³ : Field F
inst✝² : Field E
inst✝¹ : Algebra F E
rank_inf : Fact (ℵ₀ ≤ Module.rank F E)
inst✝ : Algebra.IsAlgebraic F E
i : (Module.rank F E).ord.ToType
ih : (y : (Module.rank F E).ord.ToType) → y < i → (Module.rank F E).ord.ToType
s : Set E := failed to pretty print expression (use 'set_option pp.rawOnError true' for raw representation)
this✝ : failed to pretty print expression (use 'set_option pp.rawOnError true' for raw representation)
this : ⊤ ≤ adjoin F s
⊢ False
Module: Mathlib.FieldTheory.IntermediateField.ExtendRight

Goal state before:
pp: K : Type u_1
L : Type u_2
inst✝¹¹ : Field K
inst✝¹⁰ : Field L
inst✝⁹ : Algebra K L
F : IntermediateField K L
M : Type u_3
inst✝⁸ : Field M
inst✝⁷ : Algebra K M
inst✝⁶ : Algebra L M
inst✝⁵ : IsScalarTower K L M
R : Type u_4
S : Type u_5
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra S ↥F
inst✝¹ : Algebra S M
inst✝ : IsScalarTower S (↥F) M
s : S
x : ↥(F.extendRight M)
⊢ ↥(F.extendRight M)

Tactic:
refine ⟨s • x, ?_⟩

Goal state after:
K : Type u_1
L : Type u_2
inst✝¹¹ : Field K
inst✝¹⁰ : Field L
inst✝⁹ : Algebra K L
F : IntermediateField K L
M : Type u_3
inst✝⁸ : Field M
inst✝⁷ : Algebra K M
inst✝⁶ : Algebra L M
inst✝⁵ : IsScalarTower K L M
R : Type u_4
S : Type u_5
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra S ↥F
inst✝¹ : Algebra S M
inst✝ : IsScalarTower S (↥F) M
s : S
x : ↥(F.extendRight M)
⊢ s • ↑x ∈ F.extendRight M
Module: Mathlib.FieldTheory.Galois.Profinite

Goal state before:
pp: k✝ : Type u_1
K✝ : Type u_2
inst✝⁵ : Field k✝
inst✝⁴ : Field K✝
inst✝³ : Algebra k✝ K✝
k : Type u_3
K : Type u_4
inst✝² : Field k
inst✝¹ : Field K
inst✝ : Algebra k K
σ : Gal(K/k)
L₁ L₂ : (FiniteGaloisIntermediateField k K)ᵒᵖ
π : L₁ ⟶ L₂
algInst✝ : Algebra ↥(unop L₂).toSubsemiring ↥(unop L₁).toSubsemiring := (Subsemiring.inclusion ⋯).toAlgebra
this : IsScalarTower k ↥(unop L₂).toIntermediateField ↥(unop L₁).toIntermediateField
⊢ (Hom.hom ((asProfiniteGaloisGroupFunctor k K).map π))
      ((fun L ↦ (AlgEquiv.restrictNormalHom ↥(unop L).toIntermediateField) σ) L₁) =
    (fun L ↦ (AlgEquiv.restrictNormalHom ↥(unop L).toIntermediateField) σ) L₂

Tactic:
have : IsScalarTower L₂.unop L₁.unop K := IsScalarTower.of_algebraMap_eq (congrFun rfl)

Goal state after:
k✝ : Type u_1
K✝ : Type u_2
inst✝⁵ : Field k✝
inst✝⁴ : Field K✝
inst✝³ : Algebra k✝ K✝
k : Type u_3
K : Type u_4
inst✝² : Field k
inst✝¹ : Field K
inst✝ : Algebra k K
σ : Gal(K/k)
L₁ L₂ : (FiniteGaloisIntermediateField k K)ᵒᵖ
π : L₁ ⟶ L₂
algInst✝ : Algebra ↥(unop L₂).toSubsemiring ↥(unop L₁).toSubsemiring := (Subsemiring.inclusion ⋯).toAlgebra
this✝ : IsScalarTower k ↥(unop L₂).toIntermediateField ↥(unop L₁).toIntermediateField
this : IsScalarTower (↥(unop L₂).toIntermediateField) (↥(unop L₁).toIntermediateField) K
⊢ (Hom.hom ((asProfiniteGaloisGroupFunctor k K).map π))
      ((fun L ↦ (AlgEquiv.restrictNormalHom ↥(unop L).toIntermediateField) σ) L₁) =
    (fun L ↦ (AlgEquiv.restrictNormalHom ↥(unop L).toIntermediateField) σ) L₂
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]

Goal state after:
J : Type v
inst✝ : SmallCategory J
F : J ⥤ ProfiniteGrp.{max v u}
i j : J
f : i ⟶ j
⊢ { 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
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 : ∀ i ∈ s, H i = H j → ↑(g i) ≠ ↑x
y z : G
hz : z ∈ y • ↑(H j)
⊢ z ∈ ⋃ i ∈ {x ∈ s | H x ≠ H j}, (y * x⁻¹ * g i) • ↑(H i)

Tactic:
simp_rw [Finset.mem_filter, Set.mem_iUnion]

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
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 : ∀ i ∈ s, H i = H j → ↑(g i) ≠ ↑x
y z : G
hz : z ∈ y • ↑(H j)
⊢ ∃ i, ∃ (_ : i ∈ s ∧ H i ≠ H j), z ∈ (y * x⁻¹ * g i) • ↑(H i)
Module: Mathlib.RingTheory.Algebraic.LinearIndependent

Goal state before:
pp: F : Type u_1
E : Type u_2
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
x : E
H : ∀ (p : F[X]), (aeval x) p = 0 → p = 0
s : Finset F
m : F → F
hm : ∑ i ∈ s, m i • (x - (algebraMap F E) i)⁻¹ = 0
i✝ : F
hi✝ : i✝ ∈ s
hnz : ∀ (a : F), x - (algebraMap F E) a ≠ 0
b : E := ∏ j ∈ s, (x - (algebraMap F E) j)
i : F
hi : i ∈ s
⊢ m i • ((∏ j ∈ s, (x - (algebraMap F E) j)) * (x - (algebraMap F E) i)⁻¹) =
    m i • ∏ j ∈ s.erase i, (x - (algebraMap F E) j)

Tactic:
← s.prod_erase_mul _ hi,

Goal state after:
F : Type u_1
E : Type u_2
inst✝² : Field F
inst✝¹ : Field E
inst✝ : Algebra F E
x : E
H : ∀ (p : F[X]), (aeval x) p = 0 → p = 0
s : Finset F
m : F → F
hm : ∑ i ∈ s, m i • (x - (algebraMap F E) i)⁻¹ = 0
i✝ : F
hi✝ : i✝ ∈ s
hnz : ∀ (a : F), x - (algebraMap F E) a ≠ 0
b : E := ∏ j ∈ s, (x - (algebraMap F E) j)
i : F
hi : i ∈ s
⊢ m i • ((∏ j ∈ s.erase i, (x - (algebraMap F E) j)) * (x - (algebraMap F E) i) * (x - (algebraMap F E) i)⁻¹) =
    m i • ∏ j ∈ s.erase i, (x - (algebraMap F E) j)
Module: Mathlib.FieldTheory.JacobsonNoether

Goal state before:
pp: D : Type u_1
inst✝¹ : DivisionRing D
inst✝ : Algebra.IsAlgebraic (↥k) D
H : k ≠ ⊤
p : ℕ
hp : ExpChar D p
insep : ∀ (x : D), IsSeparable (↥k) x → x ∈ k
a : D
ha : a ∉ k
ha₀ : a ≠ 0
b : D
hb1 : ((ad (↥k) D) a) b ≠ 0
m : ℕ
hm2 : ∀ (n : ℕ), p ^ m ≤ n → (⇑((ad (↥k) D) a))^[n] = 0
h_exist : ∃ n, 0 < n ∧ (⇑((ad (↥k) D) a))^[n + 1] b = 0
⊢ ∃ n, 0 < n ∧ (⇑((ad (↥k) D) a))^[n] b ≠ 0 ∧ (⇑((ad (↥k) D) a))^[n + 1] b = 0

Tactic:
refine ⟨Nat.find h_exist, ⟨(Nat.find_spec h_exist).1, ?_, (Nat.find_spec h_exist).2⟩⟩

Goal state after:
D : Type u_1
inst✝¹ : DivisionRing D
inst✝ : Algebra.IsAlgebraic (↥k) D
H : k ≠ ⊤
p : ℕ
hp : ExpChar D p
insep : ∀ (x : D), IsSeparable (↥k) x → x ∈ k
a : D
ha : a ∉ k
ha₀ : a ≠ 0
b : D
hb1 : ((ad (↥k) D) a) b ≠ 0
m : ℕ
hm2 : ∀ (n : ℕ), p ^ m ≤ n → (⇑((ad (↥k) D) a))^[n] = 0
h_exist : ∃ n, 0 < n ∧ (⇑((ad (↥k) D) a))^[n + 1] b = 0
⊢ (⇑((ad (↥k) D) a))^[Nat.find h_exist] b ≠ 0
Module: Mathlib.FieldTheory.KummerExtension

Goal state before:
pp: K : Type u
inst✝ : Field K
n m : ℕ
a : K
hm : Irreducible (X ^ m - C a)
hn :
  ∀ (E : Type u) [inst : Field E] [inst_1 : Algebra K E] (x : E),
    minpoly K x = X ^ m - C a → Irreducible (X ^ n - C (AdjoinSimple.gen K x))
⊢ Irreducible (X ^ (n * m) - C a)

Tactic:
have hm' : m ≠ 0 := by
    rintro rfl
    rw [pow_zero, ← C.map_one, ← map_sub] at hm
    exact not_irreducible_C _ hm
  simpa [pow_mul] using irreducible_comp (monic_X_pow_sub_C a hm') (monic_X_pow n) hm
    (by simpa only [Polynomial.map_pow, map_X] using hn)

Goal state after:
Module: Mathlib.FieldTheory.JacobsonNoether

Goal state before:
pp: L : Type u_2
D : Type u_3
inst✝⁴ : Field L
inst✝³ : DivisionRing D
inst✝² : Algebra L D
inst✝¹ : Algebra.IsAlgebraic L D
inst✝ : IsCentral L D
hneq : ⊥ ≠ ⊤
hcenter : Subalgebra.center L D = ⊥
ntrivial : k ≠ ⊤
φ : ↥⊥ ≃ₐ[L] ↥(Subalgebra.center L D) := ⊥.equivOfEq (Subalgebra.center L D) ⋯
equiv : L ≃+* ↥k := ((botEquiv L D).symm.trans φ).toRingEquiv
x✝¹ : Algebra L ↥k := equiv.toRingHom.toAlgebra
x✝ : Algebra (↥k) L := equiv.symm.toRingHom.toAlgebra
⊢ ∃ x ∉ ⊥, IsSeparable L x

Tactic:
have _ : IsScalarTower L (center D) D := .of_algebraMap_eq fun _ ↦ rfl

Goal state after:
L : Type u_2
D : Type u_3
inst✝⁴ : Field L
inst✝³ : DivisionRing D
inst✝² : Algebra L D
inst✝¹ : Algebra.IsAlgebraic L D
inst✝ : IsCentral L D
hneq : ⊥ ≠ ⊤
hcenter : Subalgebra.center L D = ⊥
ntrivial : k ≠ ⊤
φ : ↥⊥ ≃ₐ[L] ↥(Subalgebra.center L D) := ⊥.equivOfEq (Subalgebra.center L D) ⋯
equiv : L ≃+* ↥k := ((botEquiv L D).symm.trans φ).toRingEquiv
x✝² : Algebra L ↥k := equiv.toRingHom.toAlgebra
x✝¹ : Algebra (↥k) L := equiv.symm.toRingHom.toAlgebra
x✝ : IsScalarTower L (↥k) D
⊢ ∃ x ∉ ⊥, IsSeparable L x