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

Goal state before:
pp: case mpr
M : Type u_3
inst✝³ : Group M
α : Type u_4
inst✝² : MulAction M α
N : Type u_5
β : Type u_6
inst✝¹ : Group N
inst✝ : MulAction N β
φ : M → N
f : α →ₑ[φ] β
hφ : Function.Surjective φ
hf : Function.Bijective ⇑f
⊢ IsPreprimitive N β → IsPreprimitive M α

Tactic:
intro _
    have := (isPretransitive_congr hφ hf).mpr toIsPretransitive
    exact {
      isTrivialBlock_of_isBlock {B} hB := by
        rw [← Set.preimage_image_eq B hf.injective]
        exact IsTrivialBlock.preimage hf.injective
          (isTrivialBlock_of_isBlock (hB.image f hφ hf.injective)) }

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

Goal state before:
pp: case mp.inr
G : Type u_3
inst✝³ : Group G
X : Type u_4
inst✝² : MulAction G X
inst✝¹ : IsPretransitive G X
inst✝ : Nontrivial X
a : X
h : IsSimpleOrder (BlockMem G a)
h_bot_or_top : ∀ (a_1 : BlockMem G a), a_1 = ⊥ ∨ a_1 = ⊤ := eq_bot_or_eq_top
B : Set X
haB : a ∈ B
hB : IsBlock G B
hB' : B = ↑⊤
⊢ IsTrivialBlock B

Tactic:
right

Goal state after:
case mp.inr
G : Type u_3
inst✝³ : Group G
X : Type u_4
inst✝² : MulAction G X
inst✝¹ : IsPretransitive G X
inst✝ : Nontrivial X
a : X
h : IsSimpleOrder (BlockMem G a)
h_bot_or_top : ∀ (a_1 : BlockMem G a), a_1 = ⊥ ∨ a_1 = ⊤ := ⋯
B : Set X
haB : a ∈ B
hB : IsBlock G B
hB' : B = ↑⊤
⊢ B = Set.univ
Module: Mathlib.GroupTheory.GroupAction.Primitive

Goal state before:
pp: G : Type u_1
X : Type u_2
inst✝² : Group G
inst✝¹ : MulAction G X
inst✝ : IsPreprimitive G X
A : Set X
hfA : A.Finite
hA : A.Nonempty
hA' : A ≠ Set.univ
a b : X
h : a ≠ b
⊢ ∃ g, a ∈ g • A ∧ b ∉ g • A

Tactic:
by
  let B := ⋂ (g : G) (_ : a ∈ g • A), g • A
  suffices b ∉ B by
    rw [Set.mem_iInter] at this
    simpa only [Set.mem_iInter, not_forall, exists_prop] using this
  suffices B = {a} by rw [this]; rw [Set.mem_singleton_iff]; exact Ne.symm h
  -- B is a block hence is a trivial block
  rcases isTrivialBlock_of_isBlock (G := G) (IsBlock.of_subset a hfA) with hyp | hyp
  · -- B.subsingleton
    apply Set.Subsingleton.eq_singleton_of_mem hyp
    rw [Set.mem_iInter]; intro g; simp only [Set.mem_iInter, imp_self]
  · -- B = Set.univ: contradiction
    change B = Set.univ at hyp
    exfalso; apply hA'
    suffices ∃ g : G, a ∈ g • A by
      obtain ⟨g, hg⟩ := this
      have : B ⊆ g • A := Set.biInter_subset_of_mem hg
      rw [hyp, Set.univ_subset_iff, ← eq_inv_smul_iff] at this
      rw [this, Set.smul_set_univ]
    -- ∃ (g : M), a ∈ g • A
    obtain ⟨x, hx⟩ := hA
    obtain ⟨g, hg⟩ := MulAction.exists_smul_eq G x a
    use g, x

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

Goal state before:
pp: α : Type u_1
n : ℕ
s : Set α
inst✝ : Finite α
hs : s.ncard + n ≤ Nat.card α
⊢ ↑s.ncard + ↑n ≤ ENat.card α

Tactic:
← ENat.natCast_add,

Goal state after:
α : Type u_1
n : ℕ
s : Set α
inst✝ : Finite α
hs : s.ncard + n ≤ Nat.card α
⊢ ↑(s.ncard + n) ≤ ENat.card α
Module: Mathlib.SetTheory.Cardinal.Embedding

Goal state before:
pp: α : Type u_1
m n : ℕ
inst✝ : Finite α
hn : m + n ≤ Nat.card α
⊢ ↑m + ↑n ≤ ENat.card α

Tactic:
← ENat.natCast_add,

Goal state after:
α : Type u_1
m n : ℕ
inst✝ : Finite α
hn : m + n ≤ Nat.card α
⊢ ↑(m + n) ≤ ENat.card α
Module: Mathlib.GroupTheory.SpecificGroups.Alternating

Goal state before:
pp: case a
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
h5 : 5 ≤ Nat.card α
⊢ alternatingGroup α ≤ closure {g | g.cycleType = {2, 2}}

Tactic:
rw [← Equiv.Perm.closure_three_cycles_eq_alternating, Subgroup.closure_le]

Goal state after:
case a
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
h5 : 5 ≤ Nat.card α
⊢ {σ | σ.IsThreeCycle} ⊆ ↑(closure {g | g.cycleType = {2, 2}})
Module: Mathlib.GroupTheory.GroupAction.MultipleTransitivity

Goal state before:
pp: case inr
G : Type u_1
α : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
h2 : IsMultiplyPretransitive G α 2
this : IsPretransitive G α
B : Set α
hB : IsBlock G B
h : B.Nontrivial
⊢ IsTrivialBlock B

Tactic:
right

Goal state after:
case inr
G : Type u_1
α : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
h2 : IsMultiplyPretransitive G α 2
this : IsPretransitive G α
B : Set α
hB : IsBlock G B
h : B.Nontrivial
⊢ B = univ
Module: Mathlib.GroupTheory.GroupAction.MultipleTransitivity

Goal state before:
pp: case hα
k : ℕ
hrec :
  ∀ {G : Type u_1} [inst : Group G] {α : Type u_2} [inst_1 : MulAction G α] [Finite α],
    IsMultiplyPretransitive G α k →
      ∀ {s : Set α}, s.ncard = k → (fixingSubgroup G s).index * (Nat.card α - k)! = (Nat.card α)!
G : Type u_1
inst✝² : Group G
α : Type u_2
inst✝¹ : MulAction G α
inst✝ : Finite α
Hk : IsMultiplyPretransitive G α (k + 1)
s : Set α
hs : s.ncard = k + 1
⊢ k + 1 ≤ Nat.card α

Tactic:
rw [← hs, ← Set.ncard_univ]

Goal state after:
case hα
k : ℕ
hrec :
  ∀ {G : Type u_1} [inst : Group G] {α : Type u_2} [inst_1 : MulAction G α] [Finite α],
    IsMultiplyPretransitive G α k →
      ∀ {s : Set α}, s.ncard = k → (fixingSubgroup G s).index * (Nat.card α - k)! = (Nat.card α)!
G : Type u_1
inst✝² : Group G
α : Type u_2
inst✝¹ : MulAction G α
inst✝ : Finite α
Hk : IsMultiplyPretransitive G α (k + 1)
s : Set α
hs : s.ncard = k + 1
⊢ s.ncard ≤ univ.ncard
Module: Mathlib.GroupTheory.GroupAction.Jordan

Goal state before:
pp: case h.inr.inl
n : ℕ
hrec :
  ∀ m < n,
    ∀ {G : Type u_1} {α : Type u_2} [inst : Group G] [inst_1 : MulAction G α],
      IsPreprimitive G α →
        ∀ {s : Set α},
          s.ncard = m + 1 →
            m + 2 < Nat.card α →
              (IsPretransitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPretransitive G α 2) ∧
                (IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPreprimitive G α 2)
G : Type u_1
α : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
hG : IsPreprimitive G α
s : Set α
hsn : s.ncard = n + 1
hsn' : n + 2 < Nat.card α
this : Finite α
hs_ne_univ : s ≠ Set.univ
hs_nonempty : s.Nonempty
hn : n + 1 ≥ 2
hn1 : 2 * (n + 1) < Nat.card α
⊢ (IsPretransitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPretransitive G α 2) ∧
    (IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPreprimitive G α 2)

Tactic:
have : 1 < s.ncard := by rwa [hsn]

Goal state after:
case h.inr.inl
n : ℕ
hrec :
  ∀ m < n,
    ∀ {G : Type u_1} {α : Type u_2} [inst : Group G] [inst_1 : MulAction G α],
      IsPreprimitive G α →
        ∀ {s : Set α},
          s.ncard = m + 1 →
            m + 2 < Nat.card α →
              (IsPretransitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPretransitive G α 2) ∧
                (IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPreprimitive G α 2)
G : Type u_1
α : Type u_2
inst✝¹ : Group G
inst✝ : MulAction G α
hG : IsPreprimitive G α
s : Set α
hsn : s.ncard = n + 1
hsn' : n + 2 < Nat.card α
this✝ : Finite α
hs_ne_univ : s ≠ Set.univ
hs_nonempty : s.Nonempty
hn : n + 1 ≥ 2
hn1 : 2 * (n + 1) < Nat.card α
this : 1 < s.ncard
⊢ (IsPretransitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPretransitive G α 2) ∧
    (IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → IsMultiplyPreprimitive G α 2)
Module: Mathlib.GroupTheory.GroupAction.MultipleTransitivity

Goal state before:
pp: α : Type u_1
inst✝ : Finite α
G : Subgroup (Perm α)
this : Fintype α
hmt : IsMultiplyPretransitive (↥G) α (Fintype.card α - 1)
j : Fin (Fintype.card α - 1) ↪ Fin (Fintype.card α) := castLEEmb ⋯
k : Perm α
a✝ : k ∈ ⊤
x : Fin (Fintype.card α) ↪ α := (Fintype.equivFinOfCardEq ⋯).symm.toEmbedding
x' : Fin (Fintype.card α - 1) ↪ α := j.trans x
g : ↥G
hg' : g • x' = k • x'
hx : ∀ (x : Fin (Fintype.card α) ↪ α), Function.Surjective x.toFun
⊢ k = ↑g

Tactic:
have hgk' (i : Fin (Fintype.card α)) (hi : i.val < Fintype.card α - 1) :
      (g • x) i = (k • x) i :=
    Function.Embedding.ext_iff.mp hg' ⟨i.val, hi⟩

Goal state after:
α : Type u_1
inst✝ : Finite α
G : Subgroup (Perm α)
this : Fintype α
hmt : IsMultiplyPretransitive (↥G) α (Fintype.card α - 1)
j : Fin (Fintype.card α - 1) ↪ Fin (Fintype.card α) := castLEEmb ⋯
k : Perm α
a✝ : k ∈ ⊤
x : Fin (Fintype.card α) ↪ α := (Fintype.equivFinOfCardEq ⋯).symm.toEmbedding
x' : Fin (Fintype.card α - 1) ↪ α := j.trans x
g : ↥G
hg' : g • x' = k • x'
hx : ∀ (x : Fin (Fintype.card α) ↪ α), Function.Surjective x.toFun
hgk' : ∀ (i : Fin (Fintype.card α)), ↑i < Fintype.card α - 1 → (g • x) i = (k • x) i
⊢ k = ↑g
Module: Mathlib.GroupTheory.GroupAction.MultipleTransitivity

Goal state before:
pp: case inr.inr
α : Type u_1
inst✝ : Finite α
G : Subgroup (Perm α)
this : Fintype α
hmt : IsMultiplyPretransitive (↥G) α (Fintype.card α - 1)
j✝ : Fin (Fintype.card α - 1) ↪ Fin (Fintype.card α) := castLEEmb ⋯
k : Perm α
a✝ : k ∈ ⊤
x : Fin (Fintype.card α) ↪ α := (Fintype.equivFinOfCardEq ⋯).symm.toEmbedding
x' : Fin (Fintype.card α - 1) ↪ α := j✝.trans x
g : ↥G
hg' : g • x' = k • x'
hx : ∀ (x : Fin (Fintype.card α) ↪ α), Function.Surjective x.toFun
hgk' : ∀ (i : Fin (Fintype.card α)), ↑i < Fintype.card α - 1 → (g • x) i = (k • x) i
i : Fin (Fintype.card α)
hi : ↑i = Fintype.card α - 1
j : Fin (Fintype.card α)
hxj : (k • x) j = (g • x) i
hj : ↑j = Fintype.card α - 1
⊢ ↑j = ↑i

Tactic:
hi,

Goal state after:
case inr.inr
α : Type u_1
inst✝ : Finite α
G : Subgroup (Perm α)
this : Fintype α
hmt : IsMultiplyPretransitive (↥G) α (Fintype.card α - 1)
j✝ : Fin (Fintype.card α - 1) ↪ Fin (Fintype.card α) := castLEEmb ⋯
k : Perm α
a✝ : k ∈ ⊤
x : Fin (Fintype.card α) ↪ α := (Fintype.equivFinOfCardEq ⋯).symm.toEmbedding
x' : Fin (Fintype.card α - 1) ↪ α := j✝.trans x
g : ↥G
hg' : g • x' = k • x'
hx : ∀ (x : Fin (Fintype.card α) ↪ α), Function.Surjective x.toFun
hgk' : ∀ (i : Fin (Fintype.card α)), ↑i < Fintype.card α - 1 → (g • x) i = (k • x) i
i : Fin (Fintype.card α)
hi : ↑i = Fintype.card α - 1
j : Fin (Fintype.card α)
hxj : (k • x) j = (g • x) i
hj : ↑j = Fintype.card α - 1
⊢ ↑j = Fintype.card α - 1
Module: Mathlib.GroupTheory.GroupAction.MultipleTransitivity

Goal state before:
pp: α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
h2 : 2 ≤ Nat.card α
h2le : Nat.card α - 2 ≤ Nat.card α
this✝ : IsMultiplyPretransitive (Equiv.Perm α) α (Nat.card α)
this : IsMultiplyPretransitive (Equiv.Perm α) α (Nat.card α - 2)
x y : Fin (Nat.card α - 2) ↪ α
g : Equiv.Perm α
hg : g • x = y
h : Equiv.Perm.sign g = -1
⊢ Function.Injective ⇑x

Tactic:
exact x.2

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

Goal state before:
pp: α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
h2 : 2 ≤ Nat.card α
h2le : Nat.card α - 2 ≤ Nat.card α
this✝ : IsMultiplyPretransitive (Equiv.Perm α) α (Nat.card α)
this : IsMultiplyPretransitive (Equiv.Perm α) α (Nat.card α - 2)
x y : Fin (Nat.card α - 2) ↪ α
g : Equiv.Perm α
hg : g • x = y
h : Equiv.Perm.sign g = -1
⊢ Fintype.card α - (Finset.image (⇑x) Finset.univ).card = 2

Tactic:
Finset.univ.card_image_of_injective (by exact x.2),

Goal state after:
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
h2 : 2 ≤ Nat.card α
h2le : Nat.card α - 2 ≤ Nat.card α
this✝ : IsMultiplyPretransitive (Equiv.Perm α) α (Nat.card α)
this : IsMultiplyPretransitive (Equiv.Perm α) α (Nat.card α - 2)
x y : Fin (Nat.card α - 2) ↪ α
g : Equiv.Perm α
hg : g • x = y
h : Equiv.Perm.sign g = -1
⊢ Fintype.card α - Finset.univ.card = 2
Module: Mathlib.GroupTheory.Perm.MaximalSubgroups

Goal state before:
pp: case neg
M : Type u_1
α : Type u_2
inst✝¹ : Group M
inst✝ : MulAction M α
s : Set α
hs : ∀ a ∈ s, ∀ b ∈ s, ∃ g, g • a = b
hs' : ∀ a ∈ sᶜ, ∀ b ∈ sᶜ, ∃ g, g • a = b
hM : stabilizer M s ≠ ⊤
a b : α
g : M
ha : a ∈ s
hb : b ∈ sᶜ
hgab : g • a = b
x : α
hx : x ∈ sᶜ
k : M
hk : k • b = x
⊢ ∃ g, g • a = x

Tactic:
use k * g

Goal state after:
case h
M : Type u_1
α : Type u_2
inst✝¹ : Group M
inst✝ : MulAction M α
s : Set α
hs : ∀ a ∈ s, ∀ b ∈ s, ∃ g, g • a = b
hs' : ∀ a ∈ sᶜ, ∀ b ∈ sᶜ, ∃ g, g • a = b
hM : stabilizer M s ≠ ⊤
a b : α
g : M
ha : a ∈ s
hb : b ∈ sᶜ
hgab : g • a = b
x : α
hx : x ∈ sᶜ
k : M
hk : k • b = x
⊢ (k * g) • a = x
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
⊢ IsMultiplyPretransitive K α n

Tactic:
have : Finite α := Or.resolve_right (finite_or_infinite α) (fun _ ↦ by
    simp [Nat.card_eq_zero_of_infinite] at hα)

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
⊢ IsMultiplyPretransitive K α n
Module: Mathlib.GroupTheory.GroupAction.SubMulAction.Combination

Goal state before:
pp: α : Type u_2
inst✝ : DecidableEq α
n : ℕ
h_one_le : 1 ≤ n
hn : n < Nat.card α
hα : Nat.card α ≠ 2 * n
this✝ : Finite α
this : Fintype α
⊢ IsPreprimitive (Perm α) ↑(powersetCard α n)

Tactic:
have : IsPretransitive (Perm α) (powersetCard α n) := powersetCard.isPretransitive

Goal state after:
α : Type u_2
inst✝ : DecidableEq α
n : ℕ
h_one_le : 1 ≤ n
hn : n < Nat.card α
hα : Nat.card α ≠ 2 * n
this✝¹ : Finite α
this✝ : Fintype α
this : IsPretransitive (Perm α) ↑(powersetCard α n)
⊢ IsPreprimitive (Perm α) ↑(powersetCard α n)
Module: Mathlib.GroupTheory.GroupAction.Jordan

Goal state before:
pp: α : Type u_1
G : Subgroup (Perm α)
inst✝¹ : DecidableEq α
inst✝ : Finite α
hG : IsPreprimitive (↥G) α
g : Perm α
h2g : g.IsSwap
hg : g ∈ G
this✝ : Fintype α
hα3 : Nat.card α ≥ 3
n : ℕ
hn : Nat.card α = n + 3
hsc : (↑g.support)ᶜ.ncard = n + 1
this : IsPretransitive ↥(fixingSubgroup (↥G) (↑g.support)ᶜ) ↥(ofFixingSubgroup (↥G) (↑g.support)ᶜ)
⊢ {x | x ∈ ofFixingSubgroup (↥G) (↑g.support)ᶜ}.card = g.support.card

Tactic:
simp [SubMulAction.mem_ofFixingSubgroup_iff, support]

Goal state after:
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.IsSubnormal

Goal state before:
pp: case step.inr
G : Type u_1
inst✝ : Group G
H✝ H K : Subgroup G
HK : H ≤ K
hS : K.IsSubnormal
hN : (H.subgroupOf K).Normal
K' : Subgroup G
HK' : K < K'
hS' : K'.IsSubnormal
hN' : (K.subgroupOf K').Normal
⊢ H = ⊤ ∨ ∃ K, H < K ∧ K.IsSubnormal ∧ (H.subgroupOf K).Normal

Tactic:
right

Goal state after:
case step.inr
G : Type u_1
inst✝ : Group G
H✝ H K : Subgroup G
HK : H ≤ K
hS : K.IsSubnormal
hN : (H.subgroupOf K).Normal
K' : Subgroup G
HK' : K < K'
hS' : K'.IsSubnormal
hN' : (K.subgroupOf K').Normal
⊢ ∃ K, H < K ∧ K.IsSubnormal ∧ (H.subgroupOf K).Normal
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: case inr
G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
a : ↥(toSubgroup A B (-1))
⊢ ↑((toSubgroupEquiv φ (- -1)) ((toSubgroupEquiv φ (-1)) a)) = ↑a

Tactic:
simp only [toSubgroup_neg_one, toSubgroupEquiv_neg_one, SetLike.coe_eq_coe]
    exact φ.apply_symm_apply a

Goal state after:
Module: Mathlib.GroupTheory.MonoidLocalization.Order

Goal state before:
pp: case f
α : Type u_1
inst✝² : CommMonoid α
inst✝¹ : PartialOrder α
inst✝ : IsOrderedCancelMonoid α
s : Submonoid α
a₁ b₁ : α
a₂ b₂ : ↥s
b : Localization s
a✝ : α
b✝ : ↥s
⊢ mk a✝ b✝ ≤ b → b ≤ mk a✝ b✝ → mk a✝ b✝ = b

pp: case H
α : Type u_1
inst✝² : CommMonoid α
inst✝¹ : PartialOrder α
inst✝ : IsOrderedCancelMonoid α
s : Submonoid α
a₁ b₁ : α
a₂ b₂ : ↥s
a b : Localization s
a✝ c✝ : α
b✝ d✝ : ↥s
h✝ : (r s) (a✝, b✝) (c✝, d✝)
⊢ ⋯ = ⋯

Tactic:
on_goal 1 =>
      induction b using Localization.rec
      · simp_rw [mk_le_mk, mk_eq_mk_iff, r_iff_exists]
        exact fun hab hba => ⟨1, by rw [hab.antisymm hba]⟩

Goal state after:
case f.H
α : Type u_1
inst✝² : CommMonoid α
inst✝¹ : PartialOrder α
inst✝ : IsOrderedCancelMonoid α
s : Submonoid α
a₁ b₁ : α
a₂ b₂ : ↥s
b : Localization s
a✝¹ : α
b✝¹ : ↥s
a✝ c✝ : α
b✝ d✝ : ↥s
h✝ : (r s) (a✝, b✝) (c✝, d✝)
⊢ ⋯ = ⋯

case H
α : Type u_1
inst✝² : CommMonoid α
inst✝¹ : PartialOrder α
inst✝ : IsOrderedCancelMonoid α
s : Submonoid α
a₁ b₁ : α
a₂ b₂ : ↥s
a b : Localization s
a✝ c✝ : α
b✝ d✝ : ↥s
h✝ : (r s) (a✝, b✝) (c✝, d✝)
⊢ ⋯ = ⋯
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
a✝ b✝ : Perm ↥g.cycleFactorsFinset
hσ : a✝ ∈ {τ | ∀ (c : ↥g.cycleFactorsFinset), #(↑(τ c)).support = #(↑c).support}
hτ : b✝ ∈ {τ | ∀ (c : ↥g.cycleFactorsFinset), #(↑(τ c)).support = #(↑c).support}
⊢ a✝ * b✝ ∈ {τ | ∀ (c : ↥g.cycleFactorsFinset), #(↑(τ c)).support = #(↑c).support}

Tactic:
simp only [Subtype.forall, Set.mem_ofPred_eq, coe_mul, Function.comp_apply]

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
a✝ b✝ : Perm ↥g.cycleFactorsFinset
hσ : a✝ ∈ {τ | ∀ (c : ↥g.cycleFactorsFinset), #(↑(τ c)).support = #(↑c).support}
hτ : b✝ ∈ {τ | ∀ (c : ↥g.cycleFactorsFinset), #(↑(τ c)).support = #(↑c).support}
⊢ ∀ (a : Perm α) (b : a ∈ g.cycleFactorsFinset), #(↑(a✝ (b✝ ⟨a, b⟩))).support = #a.support
Module: Mathlib.GroupTheory.Perm.Centralizer

Goal state before:
pp: α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
g : Perm α
a : g.Basis
τ : ↥(range_toPermHom' g)
⊢ (OnCycleFactors.toPermHom g) (a.toCentralizer τ) = ↑τ

Tactic:
apply ext
  intro c
  rw [OnCycleFactors.toPermHom_apply, toCentralizer_equivariant]

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

Goal state before:
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:
rw [← Finset.card_map, map_subtype_of_cycleType]
    rw [apply_ite Finset.card, Finset.card_empty]
    split_ifs with hm'
    · rw [Equiv.Perm.card_of_cycleType, if_neg]
      obtain hm | hm := not_and_or.mp hm
      · exact hm
      · contradiction
    · rfl

Goal state after:
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
h5 : Nat.card ↥K < Nat.card G
h6 : (Nat.card ↥(comap K.subtype N)).Coprime (comap K.subtype N).index
H : Subgroup ↥K
hH : (comap K.subtype N).IsComplement' H
⊢ N.relIndex (K ⊔ N) = N.index

Tactic:
hK,

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
h5 : Nat.card ↥K < Nat.card G
h6 : (Nat.card ↥(comap K.subtype N)).Coprime (comap K.subtype N).index
H : Subgroup ↥K
hH : (comap K.subtype N).IsComplement' H
⊢ N.relIndex ⊤ = N.index
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

pp: case «4»
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 : 4 ∈ g.cycleType
hk4 : 4 ≤ 4
hk1 : 1 < 4
⊢ 4 = 2

Tactic:
· rw [← lcm_cycleType, Multiset.lcm_dvd] at hg
      exact Nat.prime_eq_prime_of_dvd_pow Nat.prime_three Nat.prime_two (hg 3 hk)

Goal state after:
case «4»
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 : 4 ∈ g.cycleType
hk4 : 4 ≤ 4
hk1 : 1 < 4
⊢ 4 = 2
Module: Mathlib.GroupTheory.SchurZassenhaus

Goal state before:
pp: case pos
G : Type u
inst✝¹ : Group G
N : Subgroup G
inst✝ : N.Normal
hN : (Nat.card ↥N).Coprime N.index
hN1 : Nat.card ↥N = 0
⊢ ∃ H, N.IsComplement' H

Tactic:
rw [hN1, Nat.coprime_zero_left, index_eq_one] at hN
    rw [hN]
    exact ⟨⊥, isComplement'_top_bot⟩

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

Goal state before:
pp: α : Type u_1
inst✝² : Finite α
inst✝¹ : DecidableEq α
inst✝ : (s : Set α) → DecidablePred fun x ↦ x ∈ s
⊢ ⊤ ≤ ⨆ s, ofSubtype.range

Tactic:
← Equiv.Perm.closure_isSwap,

Goal state after:
α : Type u_1
inst✝² : Finite α
inst✝¹ : DecidableEq α
inst✝ : (s : Set α) → DecidablePred fun x ↦ x ∈ s
⊢ closure {σ | σ.IsSwap} ≤ ⨆ s, ofSubtype.range
Module: Mathlib.GroupTheory.PushoutI

Goal state before:
pp: ι : Type u_1
G : ι → Type u_2
H : Type u_3
inst✝³ : (i : ι) → Group (G i)
inst✝² : Group H
φ : (i : ι) → H →* G i
d : Transversal φ
inst✝¹ : DecidableEq ι
inst✝ : (i : ι) → DecidableEq (G i)
i : ι
g : G i
w : NormalWord d
⊢ (of i) g • w = g • w

Tactic:
summand_smul_def,

Goal state after:
ι : Type u_1
G : ι → Type u_2
H : Type u_3
inst✝³ : (i : ι) → Group (G i)
inst✝² : Group H
φ : (i : ι) → H →* G i
d : Transversal φ
inst✝¹ : DecidableEq ι
inst✝ : (i : ι) → DecidableEq (G i)
i : ι
g : G i
w : NormalWord d
⊢ (equivPair i).symm
      (let __src := (equivPair i) w;
      { head := g * ((equivPair i) w).head, tail := __src.tail, fstIdx_ne := ⋯, normalized := ⋯ }) =
    g • w
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.KleinFour

Goal state before:
pp: case inr
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
x✝ : (kleinFour α).Normal
this : Nat.card (↥(alternatingGroup α) ⧸ kleinFour α) = 3
comm_le : commutator ↥(alternatingGroup α) ≤ kleinFour α
comm_ne_bot : commutator ↥(alternatingGroup α) ≠ ⊥
k : ↥(alternatingGroup α)
hk : k ∈ commutator ↥(alternatingGroup α)
hk' : k ≠ 1
hk22 : (↑k).cycleType = {2, 2}
g : ↥(alternatingGroup α)
hg : (↑g).cycleType = {2, 2}
⊢ g ∈ commutator ↥(alternatingGroup α)

Tactic:
· rw [← hg, ← Equiv.Perm.isConj_iff_cycleType_eq, isConj_iff] at hk22
      obtain ⟨c, hc⟩ := hk22
      rw [← MulAut.conjNormal_apply, Subtype.coe_inj] at hc
      simp only [commutator, ← hc]
      let fc : MulAut (alternatingGroup α) := MulAut.conjNormal c
      suffices (⊤ : Subgroup (alternatingGroup α)) =
        Subgroup.map fc.toMonoidHom (⊤ : Subgroup (alternatingGroup α)) by
        rw [this, ← Subgroup.map_commutator]
        refine Subgroup.mem_map_of_mem _ hk
      simp

Goal state after:
Module: Mathlib.GroupTheory.Subgroup.Saturated

Goal state before:
pp: G : Type u_1
inst✝ : Group G
H : Subgroup G
h : ∀ (n : ℤ) (g : G), g ^ n ∈ H → n = 0 ∨ g ∈ H
n : ℕ
g : G
hgn : g ^ n ∈ H.toSubmonoid
⊢ n = 0 ∨ g ∈ H.toSubmonoid

Tactic:
simpa using h n g (by simpa using hgn)

Goal state after:
Module: Mathlib.GroupTheory.SpecificGroups.ZGroup

Goal state before:
pp: case inl
G : Type u_1
G' : Type u_2
G'' : Type u_3
inst✝⁵ : Group G
inst✝⁴ : Group G'
inst✝³ : Group G''
f : G →* G'
f' : G' →* G''
inst✝² : Finite G
inst✝¹ : IsZGroup G
inst✝ : IsZGroup G''
p : ℕ
hp : Nat.Prime p
P : Sylow p G'
this : Fact (Nat.Prime p)
h_cop : (Nat.card ↥f'.ker).Coprime f'.ker.index
h : ↑P ≤ f'.ker
h_le : ↑P ≤ f.range
Q : Sylow p G
hQ : Sylow.mapSurjective ⋯ Q = P.subtype h_le
⊢ IsCyclic ↥((↑P).subgroupOf f.range)

Tactic:
rw [Sylow.ext_iff, Sylow.coe_mapSurjective, Sylow.coe_subtype] at hQ

Goal state after:
case inl
G : Type u_1
G' : Type u_2
G'' : Type u_3
inst✝⁵ : Group G
inst✝⁴ : Group G'
inst✝³ : Group G''
f : G →* G'
f' : G' →* G''
inst✝² : Finite G
inst✝¹ : IsZGroup G
inst✝ : IsZGroup G''
p : ℕ
hp : Nat.Prime p
P : Sylow p G'
this : Fact (Nat.Prime p)
h_cop : (Nat.card ↥f'.ker).Coprime f'.ker.index
h : ↑P ≤ f'.ker
h_le : ↑P ≤ f.range
Q : Sylow p G
hQ : Subgroup.map f.rangeRestrict ↑Q = (↑P).subgroupOf f.range
⊢ IsCyclic ↥((↑P).subgroupOf f.range)