mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.MaximalSubgroups

Goal state before:
pp: case inl
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
hs : sᶜ.Nontrivial
k : Perm α
hk_swap : k.IsSwap
hk_support : _root_.Disjoint s ↑k.support
hks : k • s = s
g : Perm ↑s
hsg : sign g = 1
⊢ ∃ a, toPerm a = g

Tactic:
use! Equiv.Perm.ofSubtype g

Goal state after:
case property
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
hs : sᶜ.Nontrivial
k : Perm α
hk_swap : k.IsSwap
hk_support : _root_.Disjoint s ↑k.support
hks : k • s = s
g : Perm ↑s
hsg : sign g = 1
⊢ Perm.ofSubtype g ∈ alternatingGroup α

case property
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
hs : sᶜ.Nontrivial
k : Perm α
hk_swap : k.IsSwap
hk_support : _root_.Disjoint s ↑k.support
hks : k • s = s
g : Perm ↑s
hsg : sign g = 1
⊢ ⟨Perm.ofSubtype g, ?property⟩ ∈ stabilizer (↥(alternatingGroup α)) s

case h
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
hs : sᶜ.Nontrivial
k : Perm α
hk_swap : k.IsSwap
hk_support : _root_.Disjoint s ↑k.support
hks : k • s = s
g : Perm ↑s
hsg : sign g = 1
⊢ toPerm ⟨⟨Perm.ofSubtype g, ?property⟩, ?property✝⟩ = g
Module: Mathlib.GroupTheory.Perm.MaximalSubgroups

Goal state before:
pp: α : Type u_2
inst✝ : Finite α
s : Set α
h0 : s.Nonempty
hα : s.ncard < sᶜ.ncard
h1 : sᶜ.Nonempty
this✝ : Fintype α
G : Subgroup (Perm α)
hG : stabilizer (Perm α) s < G
hG' : stabilizer (Perm α) sᶜ < G
g : Perm α
hg_swap : g.IsSwap
hg : g ∈ G
this : IsPretransitive (↥G) α
B : Set α
hB : IsBlock (↥G) B
hB' : ¬B.Subsingleton
not_isBlock_sc : ¬IsBlock (↥G) sᶜ
hB_not_le_sc : ∀ (B : Set α), IsBlock (↥G) B → B ⊆ sᶜ → B.Subsingleton
⊢ sᶜ ⊆ B

Tactic:
have hB_not_le_s (B : Set α) (hB : IsBlock G B) (hBs : B ⊆ s) : B.Subsingleton :=
    have := isPreprimitive_stabilizer_subgroup hG.le
    hB.subsingleton_of_stabilizer_lt_of_subset hB_not_le_sc hG hBs

Goal state after:
α : Type u_2
inst✝ : Finite α
s : Set α
h0 : s.Nonempty
hα : s.ncard < sᶜ.ncard
h1 : sᶜ.Nonempty
this✝ : Fintype α
G : Subgroup (Perm α)
hG : stabilizer (Perm α) s < G
hG' : stabilizer (Perm α) sᶜ < G
g : Perm α
hg_swap : g.IsSwap
hg : g ∈ G
this : IsPretransitive (↥G) α
B : Set α
hB : IsBlock (↥G) B
hB' : ¬B.Subsingleton
not_isBlock_sc : ¬IsBlock (↥G) sᶜ
hB_not_le_sc : ∀ (B : Set α), IsBlock (↥G) B → B ⊆ sᶜ → B.Subsingleton
hB_not_le_s : ∀ (B : Set α), IsBlock (↥G) B → B ⊆ s → B.Subsingleton
⊢ sᶜ ⊆ B
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.MaximalSubgroups

Goal state before:
pp: α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
h0 : s.Nontrivial
hs : s.ncard < sᶜ.ncard
this✝ : s.ncard + sᶜ.ncard = Nat.card α
h1 : sᶜ.Nontrivial
hα : 4 < Nat.card α
G : Subgroup ↥(alternatingGroup α)
hG : stabilizer (↥(alternatingGroup α)) s < G
this : IsPretransitive (↥G) α
B : Set α
hB : IsBlock (↥G) B
hB' : ¬B.Subsingleton
hsc : IsBlock (↥G) sᶜ
⊢ False

Tactic:
apply compl_ne_univ.mpr h0.nonempty -- `sᶜ ≠ univ`
    apply hsc.eq_univ_of_card_lt
    grind

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.MaximalSubgroups

Goal state before:
pp: α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
h0 : s.Nontrivial
hs : s.ncard < sᶜ.ncard
this✝¹ : s.ncard + sᶜ.ncard = Nat.card α
h1 : sᶜ.Nontrivial
hα : 4 < Nat.card α
G : Subgroup ↥(alternatingGroup α)
hG : stabilizer (↥(alternatingGroup α)) s < G
this✝ : IsPretransitive (↥G) α
B : Set α
hB : IsBlock (↥G) B
hB' : ¬B.Subsingleton
not_isBlock_sc : ¬IsBlock (↥G) sᶜ
hB_not_le_sc : ∀ (B : Set α), IsBlock (↥G) B → B ⊆ sᶜ → B.Subsingleton
hB_not_le_s : ∀ (B : Set α), IsBlock (↥G) B → B ⊆ s → B.Subsingleton
this : IsMultiplyPretransitive (↥(alternatingGroup α)) α (s.ncard + 1)
⊢ sᶜ ⊆ B

Tactic:
by
    have : ¬ B ⊆ s := fun h ↦ hB' (hB_not_le_s B hB h)
    have : ¬ B ⊆ sᶜ := fun h ↦ hB' (hB_not_le_sc B hB h)
    apply hB.compl_subset_of_stabilizer_le_of_not_subset_of_not_subset_compl
      hG.le <;> grind

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

Goal state before:
pp: α : Type u_1
K : Type u_2
inst✝¹ : Group K
inst✝ : MulAction K α
hα : Nat.card α = 2
hK : fixedPoints K α ≠ _root_.Set.univ
n : ℕ
this✝ : Finite α
this : Fintype α
φ : K →* Perm α := ⋯
f : α →ₑ[⇑φ] α := ⋯
hf : Function.Bijective ⇑f
H : Subsingleton ↥φ.range
⊢ fixedPoints K α = _root_.Set.univ

Tactic:
apply Set.eq_univ_of_univ_subset

Goal state after:
α : Type u_1
K : Type u_2
inst✝¹ : Group K
inst✝ : MulAction K α
hα : Nat.card α = 2
hK : fixedPoints K α ≠ _root_.Set.univ
n : ℕ
this✝ : Finite α
this : Fintype α
φ : K →* Perm α := ⋯
f : α →ₑ[⇑φ] α := ⋯
hf : Function.Bijective ⇑f
H : Subsingleton ↥φ.range
⊢ _root_.Set.univ ⊆ fixedPoints K α
Module: Mathlib.GroupTheory.GroupAction.SubMulAction.Combination

Goal state before:
pp: G : Type u_1
inst✝³ : Group G
α : Type u_2
inst✝² : MulAction G α
n : ℕ
inst✝¹ : DecidableEq α
hn : 1 ≤ n
hα : ↑n < ENat.card α
inst✝ : FaithfulSMul G α
⊢ FaithfulSMul G ↑(powersetCard α n)

Tactic:
faithfulSMul_iff

Goal state after:
G : Type u_1
inst✝³ : Group G
α : Type u_2
inst✝² : MulAction G α
n : ℕ
inst✝¹ : DecidableEq α
hn : 1 ≤ n
hα : ↑n < ENat.card α
inst✝ : FaithfulSMul G α
⊢ ∀ (g : G), (∀ (a : ↑(powersetCard α n)), g • a = a) → g = 1
Module: Mathlib.GroupTheory.GroupAction.SubMulAction.Combination

Goal state before:
pp: case hs
α : Type u_2
inst✝¹ : DecidableEq α
inst✝ : Fintype α
n : ℕ
h_three_le : 3 ≤ n
hn : n < Nat.card α
hα : Nat.card α ≠ 2 * n
this✝ : IsPretransitive ↥(alternatingGroup α) ↑(powersetCard α n)
this : Nontrivial ↑(powersetCard α n)
s : ↑(powersetCard α n)
⊢ Nat.card α ≠ 2 * (↑s).ncard

Tactic:
simpa only [ncard_eq]

Goal state after:
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
b : ↥B
⊢ of ↑b * t = t * of ↑(φ.symm b)

Tactic:
by
  rw [t_mul_of]; simp

Goal state after:
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
a : ↥A
⊢ of ↑(φ a) = t * of ↑a * t⁻¹

Tactic:
by
  rw [t_mul_of]; simp

Goal state after:
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: case nil
G : Type u_1
inst✝² : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
H : Type u_2
inst✝¹ : Group H
M : Type u_3
inst✝ : Monoid M
d : TransversalPair G A B
motive : NormalWord d → Sort u_4
ofGroup : (g : G) → motive (NormalWord.ofGroup g)
cons :
  (g : G) →
    (u : ℤˣ) →
      (w : NormalWord d) →
        (h1 : w.head ∈ d.set u) →
          (h2 : ∀ u' ∈ Option.map Prod.fst w.toList.head?, w.head ∈ toSubgroup A B u → u = u') →
            motive w → motive (NormalWord.cons g u w h1 h2)
g : G
chain : List.IsChain (fun a b ↦ a.2 ∈ toSubgroup A B a.1 → a.1 = b.1) []
mem_set : ∀ (u : ℤˣ) (g_1 : G), (u, g_1) ∈ { head := g, toList := [], chain := chain }.toList → g_1 ∈ d.set u
⊢ motive { head := g, toList := [], chain := chain, mem_set := mem_set }

Tactic:
| nil =>

Goal state after:
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: case pos.cons
G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
d : TransversalPair G A B
g : ↥A
g✝ : G
u✝ : ℤˣ
w✝ : NormalWord d
h1✝ : w✝.head ∈ d.set u✝
h2✝ : ∀ u' ∈ Option.map Prod.fst w✝.toList.head?, w✝.head ∈ toSubgroup A B u✝ → u✝ = u'
this : Cancels 1 (↑g • cons g✝ u✝ w✝ h1✝ h2✝) ↔ Cancels 1 (cons g✝ u✝ w✝ h1✝ h2✝)
hcan : Cancels 1 (cons g✝ u✝ w✝ h1✝ h2✝)
a✝ :
  cons g✝ u✝ w✝ h1✝ h2✝ = w✝ →
    consRecOn (motive := fun x ↦ Cancels 1 x → NormalWord d) (↑g • cons g✝ u✝ w✝ h1✝ h2✝)
        (fun g_1 a ↦ ↑g • cons g✝ u✝ w✝ h1✝ h2✝) (fun g x w x_1 x_2 x_3 can ↦ ↑(φ ⟨g, ⋯⟩) • w) ⋯ =
      ↑(φ g) •
        consRecOn (motive := fun x ↦ Cancels 1 x → NormalWord d) (cons g✝ u✝ w✝ h1✝ h2✝)
          (fun g a ↦ cons g✝ u✝ w✝ h1✝ h2✝) (fun g x w x_1 x_2 x_3 can ↦ ↑(φ ⟨g, ⋯⟩) • w) hcan
⊢ ↑(φ ⟨↑g * g✝, ⋯⟩) • w✝ = (↑(φ g) * ↑(φ ⟨g✝, ⋯⟩)) • w✝

Tactic:
← Subgroup.coe_mul,

Goal state after:
case pos.cons
G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
d : TransversalPair G A B
g : ↥A
g✝ : G
u✝ : ℤˣ
w✝ : NormalWord d
h1✝ : w✝.head ∈ d.set u✝
h2✝ : ∀ u' ∈ Option.map Prod.fst w✝.toList.head?, w✝.head ∈ toSubgroup A B u✝ → u✝ = u'
this : Cancels 1 (↑g • cons g✝ u✝ w✝ h1✝ h2✝) ↔ Cancels 1 (cons g✝ u✝ w✝ h1✝ h2✝)
hcan : Cancels 1 (cons g✝ u✝ w✝ h1✝ h2✝)
a✝ :
  cons g✝ u✝ w✝ h1✝ h2✝ = w✝ →
    consRecOn (motive := fun x ↦ Cancels 1 x → NormalWord d) (↑g • cons g✝ u✝ w✝ h1✝ h2✝)
        (fun g_1 a ↦ ↑g • cons g✝ u✝ w✝ h1✝ h2✝) (fun g x w x_1 x_2 x_3 can ↦ ↑(φ ⟨g, ⋯⟩) • w) ⋯ =
      ↑(φ g) •
        consRecOn (motive := fun x ↦ Cancels 1 x → NormalWord d) (cons g✝ u✝ w✝ h1✝ h2✝)
          (fun g a ↦ cons g✝ u✝ w✝ h1✝ h2✝) (fun g x w x_1 x_2 x_3 can ↦ ↑(φ ⟨g, ⋯⟩) • w) hcan
⊢ ↑(φ ⟨↑g * g✝, ⋯⟩) • w✝ = ↑(φ g * φ ⟨g✝, ⋯⟩) • w✝
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: case nil
G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
d : TransversalPair G A B
w : ReducedWord G A B
chain : List.IsChain (fun a b ↦ a.2 ∈ toSubgroup A B a.1 → a.1 = b.1) []
⊢ ∃ w',
    ReducedWord.prod φ w'.toReducedWord = ReducedWord.prod φ { head := 1, toList := [], chain := chain } ∧
      List.map Prod.fst w'.toList = List.map Prod.fst { head := 1, toList := [], chain := chain }.toList ∧
        ∀ u ∈ Option.map Prod.fst { head := 1, toList := [], chain := chain }.toList.head?,
          w'.head ∈ toSubgroup A B (-u)

Tactic:
| nil =>

Goal state after:
Module: Mathlib.GroupTheory.Perm.ClosureSwap

Goal state before:
pp: case refine_1
α : Type u_2
inst✝ : DecidableEq α
S : Set (Equiv.Perm α)
hS : ∀ f ∈ S, f.IsSwap
supp : Set α
fin : supp.Finite
a : α
s : Set α
ih : ∀ {f : Equiv.Perm α}, (∀ (x : α), f x ∈ orbit (↥(closure S)) x) → (fixedBy α f)ᶜ ⊆ s → f ∈ closure S
f : Equiv.Perm α
hf : ∀ (x : α), f x ∈ orbit (↥(closure S)) x
supp_subset : (fixedBy α f)ᶜ ⊆ insert a s
b : α
⊢ (Equiv.swap (f a) a * f) b ∈ orbit (↥(closure S)) b

pp: case refine_2
α : Type u_2
inst✝ : DecidableEq α
S : Set (Equiv.Perm α)
hS : ∀ f ∈ S, f.IsSwap
supp : Set α
fin : supp.Finite
a : α
s : Set α
ih : ∀ {f : Equiv.Perm α}, (∀ (x : α), f x ∈ orbit (↥(closure S)) x) → (fixedBy α f)ᶜ ⊆ s → f ∈ closure S
f : Equiv.Perm α
hf : ∀ (x : α), f x ∈ orbit (↥(closure S)) x
supp_subset : (fixedBy α f)ᶜ ⊆ insert a s
b : α
hb : b ∈ (fixedBy α (Equiv.swap (f a) a * f))ᶜ
⊢ b ∈ s

Tactic:
· rw [Perm.mul_apply, swap_apply_def]; split_ifs with h1 h2
    · rw [← orbit_eq_iff.mpr (hf b), h1, orbit_eq_iff.mpr (hf a)]; apply mem_orbit_self
    · rw [← orbit_eq_iff.mpr (hf b), h2]; apply hf
    · exact hf b

Goal state after:
case refine_2
α : Type u_2
inst✝ : DecidableEq α
S : Set (Equiv.Perm α)
hS : ∀ f ∈ S, f.IsSwap
supp : Set α
fin : supp.Finite
a : α
s : Set α
ih : ∀ {f : Equiv.Perm α}, (∀ (x : α), f x ∈ orbit (↥(closure S)) x) → (fixedBy α f)ᶜ ⊆ s → f ∈ closure S
f : Equiv.Perm α
hf : ∀ (x : α), f x ∈ orbit (↥(closure S)) x
supp_subset : (fixedBy α f)ᶜ ⊆ insert a s
b : α
hb : b ∈ (fixedBy α (Equiv.swap (f a) a * f))ᶜ
⊢ b ∈ s
Module: Mathlib.GroupTheory.SchurZassenhaus

Goal state before:
pp: G : Type u
inst✝² : Group G
N : Subgroup G
inst✝¹ : N.Normal
h1 : (Nat.card ↥N).Coprime N.index
h2 :
  ∀ (G' : Type u) [inst : Group G'] [Finite G'],
    Nat.card G' < Nat.card G →
      ∀ {N' : Subgroup G'} [N'.Normal], (Nat.card ↥N').Coprime N'.index → ∃ H', N'.IsComplement' H'
inst✝ : Finite G
K : Subgroup G
hK : K ⊔ N = ⊤
h3 : K ≠ ⊤
h4 : (comap K.subtype N).index = N.index
⊢ Nat.card ↥K < Nat.card G

Tactic:
← K.index_mul_card

Goal state after:
G : Type u
inst✝² : Group G
N : Subgroup G
inst✝¹ : N.Normal
h1 : (Nat.card ↥N).Coprime N.index
h2 :
  ∀ (G' : Type u) [inst : Group G'] [Finite G'],
    Nat.card G' < Nat.card G →
      ∀ {N' : Subgroup G'} [N'.Normal], (Nat.card ↥N').Coprime N'.index → ∃ H', N'.IsComplement' H'
inst✝ : Finite G
K : Subgroup G
hK : K ⊔ N = ⊤
h3 : K ≠ ⊤
h4 : (comap K.subtype N).index = N.index
⊢ Nat.card ↥K < K.index * Nat.card ↥K
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.Centralizer

Goal state before:
pp: case pos
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
m : Multiset ℕ
hm : (m.sum ≤ Fintype.card α ∧ ∀ a ∈ m, 2 ≤ a) ∧ Even (m.sum + m.card)
⊢ #{g | (↑g).cycleType = m} =
    (Fintype.card α)! / ((Fintype.card α - m.sum)! * (m.prod * ∏ n ∈ m.toFinset, (Multiset.count n m)!))

pp: case neg
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
m : Multiset ℕ
hm : ¬((m.sum ≤ Fintype.card α ∧ ∀ a ∈ m, 2 ≤ a) ∧ Even (m.sum + m.card))
⊢ #{g | (↑g).cycleType = m} = 0

Tactic:
· -- m is an even cycle_type
    rw [← Finset.card_map, map_subtype_of_cycleType, if_pos hm.2,
      Equiv.Perm.card_of_cycleType α m, if_pos hm.1, mul_assoc]

Goal state after:
case neg
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
m : Multiset ℕ
hm : ¬((m.sum ≤ Fintype.card α ∧ ∀ a ∈ m, 2 ≤ a) ∧ Even (m.sum + m.card))
⊢ #{g | (↑g).cycleType = m} = 0
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: case a
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
p : ↥(centralizer {g})
u : Perm ↑(Function.fixedPoints ⇑g) := (↑p).subtypePerm ⋯
hp :
  ∀ c ∈ g.cycleFactorsFinset,
    ∃ (hc : ∀ (x : α), ↑p x ∈ c.support ↔ x ∈ c.support), ofSubtype ((↑p).subtypePerm hc) ∈ zpowers c
⊢ ↑p ∈ (kerParam g).range

Tactic:
set v : (c : g.cycleFactorsFinset) → (Subgroup.zpowers c.val) :=
      fun c => ⟨ofSubtype
          (p.1.subtypePerm (Classical.choose (hp c.val c.prop))),
            Classical.choose_spec (hp c.val c.prop)⟩

Goal state after:
case a
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
p : ↥(centralizer {g})
u : Perm ↑(Function.fixedPoints ⇑g) := (↑p).subtypePerm ⋯
hp :
  ∀ c ∈ g.cycleFactorsFinset,
    ∃ (hc : ∀ (x : α), ↑p x ∈ c.support ↔ x ∈ c.support), ofSubtype ((↑p).subtypePerm hc) ∈ zpowers c
v : (c : ↥g.cycleFactorsFinset) → ↥(zpowers ↑c) := fun c ↦ ⟨ofSubtype ((↑p).subtypePerm ⋯), ⋯⟩
⊢ ↑p ∈ (kerParam g).range
Module: Mathlib.GroupTheory.SchurZassenhaus

Goal state before:
pp: G : Type u
inst✝³ : Group G
N : Subgroup G
inst✝² : N.Normal
h1 : (Nat.card ↥N).Coprime N.index
h2 :
  ∀ (G' : Type u) [inst : Group G'] [Finite G'],
    Nat.card G' < Nat.card G →
      ∀ {N' : Subgroup G'} [N'.Normal], (Nat.card ↥N').Coprime N'.index → ∃ H', N'.IsComplement' H'
h3 : ∀ (H : Subgroup G), ¬N.IsComplement' H
inst✝¹ : Finite G
K : Subgroup G
inst✝ : K.Normal
hK : K ≤ N
this : Function.Surjective ⇑(QuotientGroup.mk' K)
h4 : K ≠ ⊥ ∧ K ≠ N
⊢ K.index < Nat.card G

Tactic:
← K.index_mul_card

Goal state after:
G : Type u
inst✝³ : Group G
N : Subgroup G
inst✝² : N.Normal
h1 : (Nat.card ↥N).Coprime N.index
h2 :
  ∀ (G' : Type u) [inst : Group G'] [Finite G'],
    Nat.card G' < Nat.card G →
      ∀ {N' : Subgroup G'} [N'.Normal], (Nat.card ↥N').Coprime N'.index → ∃ H', N'.IsComplement' H'
h3 : ∀ (H : Subgroup G), ¬N.IsComplement' H
inst✝¹ : Finite G
K : Subgroup G
inst✝ : K.Normal
hK : K ≤ N
this : Function.Surjective ⇑(QuotientGroup.mk' K)
h4 : K ≠ ⊥ ∧ K ≠ N
⊢ K.index < K.index * Nat.card ↥K
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
k : Perm ↑(Function.fixedPoints ⇑g)
v : (c : ↥g.cycleFactorsFinset) → ↥(zpowers ↑c)
⊢ g.cycleFactorsFinset.attach.noncommProd (fun i ↦ (sign.comp (zpowers ↑i).subtype) (((k, v).1, (k, v).2).2 i)) ⋯ =
    ∏ c ∈ g.cycleFactorsFinset.attach, sign ↑(v c)

Tactic:
Finset.noncommProd_eq_prod

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
k : Perm ↑(Function.fixedPoints ⇑g)
v : (c : ↥g.cycleFactorsFinset) → ↥(zpowers ↑c)
⊢ ∏ i ∈ g.cycleFactorsFinset.attach, (sign.comp (zpowers ↑i).subtype) (((k, v).1, (k, v).2).2 i) =
    ∏ c ∈ g.cycleFactorsFinset.attach, sign ↑(v c)
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
k : Perm ↑(Function.fixedPoints ⇑g)
v : (c : ↥g.cycleFactorsFinset) → ↥(zpowers ↑c)
U : Set ↥g.cycleFactorsFinset := ⋯
c : ↥g.cycleFactorsFinset
x✝¹ : c ∈ U
d : ↥g.cycleFactorsFinset
x✝ : d ∈ U
h : c ≠ d
m : ℤ
hm : (fun x ↦ ↑c ^ x) m = ↑(v c)
n : ℤ
hn : (fun x ↦ ↑d ^ x) n = ↑(v d)
⊢ ↑c ≠ ↑d

Tactic:
exact Subtype.coe_ne_coe.mpr h

Goal state after:
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
⊢ Nat.card ↑{h | IsConj g h} =
    (Fintype.card α)! /
      ((Fintype.card α - g.cycleType.sum)! * g.cycleType.prod *
        ∏ n ∈ g.cycleType.toFinset, (Multiset.count n g.cycleType)!)

Tactic:
rw [← card_isConj_mul_eq g, Nat.div_eq_of_eq_mul_left _]

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
⊢ Nat.card ↑{h | IsConj g h} *
      ((Fintype.card α - g.cycleType.sum)! * g.cycleType.prod *
        ∏ n ∈ g.cycleType.toFinset, (Multiset.count n g.cycleType)!) =
    Nat.card ↑{h | IsConj g h} *
      ((Fintype.card α - g.cycleType.sum)! * g.cycleType.prod *
        ∏ n ∈ g.cycleType.toFinset, (Multiset.count n g.cycleType)!)

α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
⊢ 0 <
    (Fintype.card α - g.cycleType.sum)! * g.cycleType.prod * ∏ n ∈ g.cycleType.toFinset, (Multiset.count n g.cycleType)!
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
⊢ Nat.card ↑{h | IsConj g h} =
    (Fintype.card α)! /
      ((Fintype.card α - g.cycleType.sum)! * g.cycleType.prod *
        ∏ n ∈ g.cycleType.toFinset, (Multiset.count n g.cycleType)!)

Tactic:
rw [← card_isConj_mul_eq g, Nat.div_eq_of_eq_mul_left _]
  · rfl
  -- This is the cardinal of the centralizer
  · rw [← nat_card_centralizer g]
    apply Nat.card_pos

Goal state after:
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
⊢ Nat.card ↑{h | IsConj g h} =
    (Fintype.card α)! /
      ((Fintype.card α - g.cycleType.sum)! * g.cycleType.prod *
        ∏ n ∈ g.cycleType.toFinset, (Multiset.count n g.cycleType)!)

Tactic:
by
  rw [← card_isConj_mul_eq g, Nat.div_eq_of_eq_mul_left _]
  · rfl
  -- This is the cardinal of the centralizer
  · rw [← nat_card_centralizer g]
    apply Nat.card_pos

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.KleinFour

Goal state before:
pp: case «3»
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
g : Perm α
hg0 : (-1) ^ (g.cycleType.sum + g.cycleType.card) = 1
n : ℕ
hg : orderOf g ∣ 2 ^ n
h1 : g.cycleType.sum ≤ 4
k : ℕ
hk : 3 ∈ g.cycleType
hk4 : 3 ≤ 4
hk1 : 1 < 3
⊢ 3 = 2

Tactic:
← lcm_cycleType,

Goal state after:
case «3»
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
g : Perm α
hg0 : (-1) ^ (g.cycleType.sum + g.cycleType.card) = 1
n : ℕ
hg : g.cycleType.lcm ∣ 2 ^ n
h1 : g.cycleType.sum ≤ 4
k : ℕ
hk : 3 ∈ g.cycleType
hk4 : 3 ≤ 4
hk1 : 1 < 3
⊢ 3 = 2
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.Simple

Goal state before:
pp: α : Type u_2
inst✝² : DecidableEq α
inst✝¹ : Fintype α
hα : 5 ≤ Nat.card α
N : Subgroup (Perm α)
inst✝ : N.Normal
ntN : Nontrivial ↥N
this : IsPreprimitive (Perm α) ↑(Set.powersetCard α 2)
⊢ fixedPoints ↥N ↑(Set.powersetCard α 2) ≠ _root_.Set.univ

Tactic:
exact fixedPoints_ne_univ_of_faithfulSMul (by norm_num) (by grind)

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.KleinFour

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
this : Monoid.exponent ↥(kleinFour α) ∣ 2
⊢ Monoid.exponent ↥(kleinFour α) = 2

Tactic:
rw [Nat.dvd_prime Nat.prime_two] at this

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
this : Monoid.exponent ↥(kleinFour α) = 1 ∨ Monoid.exponent ↥(kleinFour α) = 2
⊢ Monoid.exponent ↥(kleinFour α) = 2
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.Simple

Goal state before:
pp: α : Type u_1
inst✝² : DecidableEq α
inst✝¹ : Fintype α
hα : 5 ≤ Nat.card α
hα' : Nat.card α ≠ 6
N : Subgroup ↥(alternatingGroup α)
inst✝ : N.Normal
hN : Nontrivial ↥N
this : IsPreprimitive ↥(alternatingGroup α) ↑(Set.powersetCard α 3)
⊢ fixedPoints ↥N ↑(Set.powersetCard α 3) ≠ Set.univ

Tactic:
exact fixedPoints_ne_univ_of_faithfulSMul (by norm_num) (by grind)

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.Simple

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
s : Finset α
hs : s.card = 4
g : ↥(alternatingGroup α)
⊢ Subgroup.map (ofSubtype (g • s)) (kleinFour ↥(g • s)) = MulAut.conj g • Subgroup.map (ofSubtype s) (kleinFour ↥s)

Tactic:
rcases g with ⟨g, hg⟩

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
s : Finset α
hs : s.card = 4
g : Perm α
hg : g ∈ alternatingGroup α
⊢ Subgroup.map (ofSubtype (⟨g, hg⟩ • s)) (kleinFour ↥(⟨g, hg⟩ • s)) =
    MulAut.conj ⟨g, hg⟩ • Subgroup.map (ofSubtype s) (kleinFour ↥s)
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.Simple

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
h5 : 5 ≤ Nat.card α
s : ↑(Set.powersetCard α 4)
⊢ IsMulCommutative ↥(Subgroup.map (ofSubtype ↑s) (kleinFour ↥↑s))

Tactic:
by
    have : IsMulCommutative (kleinFour s) :=
      (kleinFour_isKleinFour (by simp)).isMulCommutative
    infer_instance

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.Simple

Goal state before:
pp: α : Type u_1
inst✝² : DecidableEq α
inst✝¹ : Fintype α
hα : 5 ≤ Nat.card α
hα' : Nat.card α ≠ 8
N : Subgroup ↥(alternatingGroup α)
inst✝ : N.Normal
hN : Nontrivial ↥N
this : IsPreprimitive ↥(alternatingGroup α) ↑(Set.powersetCard α 4)
⊢ fixedPoints ↥N ↑(Set.powersetCard α 4) ≠ Set.univ

Tactic:
exact fixedPoints_ne_univ_of_faithfulSMul (by norm_num) (by grind)

Goal state after:
Module: Mathlib.GroupTheory.PushoutI

Goal state before:
pp: ι : Type u_1
G : ι → Type u_2
H : Type u_3
inst✝¹ : (i : ι) → Group (G i)
inst✝ : Group H
φ : (i : ι) → H →* G i
hφ : ∀ (i : ι), Injective ⇑(φ i)
w : Word G
hw : Reduced φ w
h : ofCoprodI w.prod ∈ (base φ).range
⊢ w = Word.empty

Tactic:
by
  rcases transversal_nonempty φ hφ with ⟨d⟩
  rcases hw.exists_normalWord_prod_eq d with ⟨w', hw'prod, hw'map⟩
  rcases h with ⟨h, heq⟩
  have : (NormalWord.prod (d := d) ⟨.empty, h, by simp⟩) = base φ h := by
    simp [NormalWord.prod]
  rw [← hw'prod, ← this] at heq
  suffices w'.toWord = .empty by
    simp [this, @eq_comm _ []] at hw'map
    ext
    simp [hw'map]
  rw [← prod_injective heq]

Goal state after:
Module: Mathlib.Probability.Kernel.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ η : Kernel α β
s : Set α
hs : MeasurableSet s
inst✝² : DecidablePred fun x ↦ x ∈ s
inst✝¹ : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
a : α
⊢ (piecewise hs κ η) a = Measure.sum fun n ↦ (piecewise hs (κ.seq n) (η.seq n)) a

Tactic:
Kernel.piecewise_apply

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ η : Kernel α β
s : Set α
hs : MeasurableSet s
inst✝² : DecidablePred fun x ↦ x ∈ s
inst✝¹ : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
a : α
⊢ (if a ∈ s then κ a else η a) = Measure.sum fun n ↦ if a ∈ s then (κ.seq n) a else (η.seq n) a
Module: Mathlib.Probability.Kernel.MeasurableLIntegral

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
f : α → β → ℝ≥0∞
hf : Measurable (uncurry f)
F : ℕ → SimpleFunc (α × β) ℝ≥0∞ := SimpleFunc.eapprox (uncurry f)
h : ∀ (a : α) (b : β), ⨆ n, (F n) (a, b) = f a b
⊢ Measurable fun a ↦ ∫⁻ (b : β), ⨆ n, (F n) (a, b) ∂κ a

Tactic:
have : ∀ a, (∫⁻ b, ⨆ n, F n (a, b) ∂κ a) = ⨆ n, ∫⁻ b, F n (a, b) ∂κ a := by
    intro a
    rw [lintegral_iSup]
    · exact fun n => (F n).measurable.comp measurable_prodMk_left
    · exact fun i j hij b => SimpleFunc.monotone_eapprox (uncurry f) hij _

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
f : α → β → ℝ≥0∞
hf : Measurable (uncurry f)
F : ℕ → SimpleFunc (α × β) ℝ≥0∞ := SimpleFunc.eapprox (uncurry f)
h : ∀ (a : α) (b : β), ⨆ n, (F n) (a, b) = f a b
this : ∀ (a : α), ∫⁻ (b : β), ⨆ n, (F n) (a, b) ∂κ a = ⨆ n, ∫⁻ (b : β), (F n) (a, b) ∂κ a
⊢ Measurable fun a ↦ ∫⁻ (b : β), ⨆ n, (F n) (a, b) ∂κ a