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

Goal state before:
pp: case inr
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
hα : 4 < Nat.card α
hs : 2 ≥ s.ncard
this : s.ncard + sᶜ.ncard = Nat.card α
⊢ ∃ g ∈ stabilizer (Perm α) s, g.IsThreeCycle

Tactic:
rw [← stabilizer_compl]

Goal state after:
case inr
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
hα : 4 < Nat.card α
hs : 2 ≥ s.ncard
this : s.ncard + sᶜ.ncard = Nat.card α
⊢ ∃ g ∈ stabilizer (Perm α) sᶜ, g.IsThreeCycle
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.MaximalSubgroups

Goal state before:
pp: 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
a✝ : α
⊢ a✝ ∈ k • s → a✝ ∈ s

Tactic:
simp only [mem_smul_set]

Goal state after:
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
a✝ : α
⊢ (∃ y ∈ s, k • y = a✝) → a✝ ∈ s
Module: Mathlib.GroupTheory.Perm.MaximalSubgroups

Goal state before:
pp: α : Type u_2
inst✝ : DecidableEq α
s : Set α
G : Subgroup (Perm α)
hG : stabilizer (Perm α) s < G
this : ∀ (t : Set α), 1 < t.encard → ∃ g, g.IsSwap ∧ g ∈ stabilizer (Perm α) t
h1' : s.encard ≤ 1
h1c' : sᶜ.encard ≤ 1
hα : univ.encard = 2
x✝ : Finite α
⊢ Nat.card α = 2

Tactic:
rw [← ENat.card_coe_set_eq, ENat.card_eq_coe_natCard, Nat.card_coe_set_eq, ncard_univ] at hα

Goal state after:
α : Type u_2
inst✝ : DecidableEq α
s : Set α
G : Subgroup (Perm α)
hG : stabilizer (Perm α) s < G
this : ∀ (t : Set α), 1 < t.encard → ∃ g, g.IsSwap ∧ g ∈ stabilizer (Perm α) t
h1' : s.encard ≤ 1
h1c' : sᶜ.encard ≤ 1
hα : ↑(Nat.card α) = 2
x✝ : Finite α
⊢ Nat.card α = 2
Module: Mathlib.GroupTheory.GroupAction.Jordan

Goal state before:
pp: n : ℕ
hrec :
  ∀ {G : Type u_1} {α : Type u_2} [inst : Group G] [inst_1 : MulAction G α],
    IsPreprimitive G α →
      ∀ {s : Set α},
        s.ncard = n + 1 →
          n + 2 < Nat.card α →
            IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → Finite α → IsMultiplyPreprimitive G α (n + 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 + 1
hsn' : n + 1 + 2 < Nat.card α
hprim : IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s)
hα : Finite α
a : α
t : Set ↥(ofStabilizer G a)
left✝ : a ∈ s
hst : s = insert a (Subtype.val '' t)
ha' : a ∉ Subtype.val '' t
⊢ IsMultiplyPreprimitive G α (n + 1 + 2)

Tactic:
have ht_prim : IsPreprimitive (stabilizer G a) (SubMulAction.ofStabilizer G a) := by
        rw [← is_one_preprimitive_iff]
        rw [← isMultiplyPreprimitive_succ_iff_ofStabilizer]
        · apply is_two_preprimitive hG hsn hsn' hprim
        · norm_num

Goal state after:
n : ℕ
hrec :
  ∀ {G : Type u_1} {α : Type u_2} [inst : Group G] [inst_1 : MulAction G α],
    IsPreprimitive G α →
      ∀ {s : Set α},
        s.ncard = n + 1 →
          n + 2 < Nat.card α →
            IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s) → Finite α → IsMultiplyPreprimitive G α (n + 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 + 1
hsn' : n + 1 + 2 < Nat.card α
hprim : IsPreprimitive ↥(fixingSubgroup G s) ↥(ofFixingSubgroup G s)
hα : Finite α
a : α
t : Set ↥(ofStabilizer G a)
left✝ : a ∈ s
hst : s = insert a (Subtype.val '' t)
ha' : a ∉ Subtype.val '' t
ht_prim : IsPreprimitive ↥(stabilizer G a) ↥(ofStabilizer G a)
⊢ IsMultiplyPreprimitive G α (n + 1 + 2)
Module: Mathlib.GroupTheory.Perm.MaximalSubgroups

Goal state before:
pp: case inr.inr
α : Type u_2
inst✝ : Finite α
s : Set α
hs_nonempty : s.Nonempty
hsc_nonempty : sᶜ.Nonempty
hα : Nat.card α ≠ 2 * s.ncard
h : sᶜ.ncard < s.ncard
⊢ IsCoatom (stabilizer (Perm α) s)

Tactic:
rw [← stabilizer_compl]

Goal state after:
case inr.inr
α : Type u_2
inst✝ : Finite α
s : Set α
hs_nonempty : s.Nonempty
hsc_nonempty : sᶜ.Nonempty
hα : Nat.card α ≠ 2 * s.ncard
h : sᶜ.ncard < s.ncard
⊢ IsCoatom (stabilizer (Perm α) sᶜ)
Module: Mathlib.GroupTheory.SpecificGroups.Alternating.MaximalSubgroups

Goal state before:
pp: case inr
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
h0 : s.Nonempty
h1 : sᶜ.Nonempty
hs : ¬sᶜ.ncard = s.ncard
this :
  ∀ {α : Type u_1} [inst : Fintype α] [inst_1 : DecidableEq α] {s : Set α},
    s.Nonempty →
      sᶜ.Nonempty → ¬sᶜ.ncard = s.ncard → s.ncard < sᶜ.ncard → IsCoatom (stabilizer (↥(alternatingGroup α)) s)
hs' : ¬s.ncard < sᶜ.ncard
⊢ IsCoatom (stabilizer (↥(alternatingGroup α)) s)

Tactic:
rw [← stabilizer_compl]

Goal state after:
case inr
α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
s : Set α
h0 : s.Nonempty
h1 : sᶜ.Nonempty
hs : ¬sᶜ.ncard = s.ncard
this :
  ∀ {α : Type u_1} [inst : Fintype α] [inst_1 : DecidableEq α] {s : Set α},
    s.Nonempty →
      sᶜ.Nonempty → ¬sᶜ.ncard = s.ncard → s.ncard < sᶜ.ncard → IsCoatom (stabilizer (↥(alternatingGroup α)) s)
hs' : ¬s.ncard < sᶜ.ncard
⊢ IsCoatom (stabilizer (↥(alternatingGroup α)) sᶜ)
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: G : Type u_1
inst✝ : Group G
A B : Subgroup G
φ : ↥A ≃* ↥B
motive : HNNExtension G A B φ → Prop
x : HNNExtension G A B φ
of : ∀ (g : G), motive (HNNExtension.of g)
t : motive HNNExtension.t
mul : ∀ (x y : HNNExtension G A B φ), motive x → motive y → motive (x * y)
inv : ∀ (x : HNNExtension G A B φ), motive x → motive x⁻¹
⊢ motive x

Tactic:
let S : Subgroup (HNNExtension G A B φ) :=
    { carrier := Set.ofPred motive
      one_mem' := by simpa using of 1
      mul_mem' := mul _ _
      inv_mem' := inv _ }
  let f : HNNExtension G A B φ →* S :=
    lift (HNNExtension.of.codRestrict S of)
      ⟨HNNExtension.t, t⟩ (by intro a; ext; simp [equiv_eq_conj, mul_assoc])
  have hf : S.subtype.comp f = MonoidHom.id _ :=
    hom_ext (by ext; simp [f]) (by simp [f])
  change motive (MonoidHom.id _ x)
  rw [← hf]
  exact (f x).2

Goal state after:
Module: Mathlib.GroupTheory.IsSubnormal

Goal state before:
pp: case step.inl
G : Type u_1
inst✝ : Group G
H✝ H : Subgroup G
ne_top : H ≠ ⊤
h_le : H ≤ ⊤
hSubn : ⊤.IsSubnormal
hN : (H.subgroupOf ⊤).Normal
ih : ⊤ ≠ ⊤ → ∃ K, K.Normal ∧ ⊤ ≤ K ∧ K < ⊤
⊢ ∃ K, K.Normal ∧ H ≤ K ∧ K < ⊤

Tactic:
rw [normal_subgroupOf_iff_le_normalizer h_le, top_le_iff, normalizer_eq_top_iff] at hN
      exact ⟨H, hN, le_rfl, ne_top.lt_top⟩

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

Goal state before:
pp: α : Type u_1
ι : Type u_2
f : α → ι
g : (i : ι) → Perm { a // f a = i }
a : α
⊢ stabilizerEquiv_invFun (fun i ↦ Equiv.symm (g i)) (stabilizerEquiv_invFun g a) = a

Tactic:
rw [stabilizerEquiv_invFun_eq _ (comp_stabilizerEquiv_invFun g a)]

Goal state after:
α : Type u_1
ι : Type u_2
f : α → ι
g : (i : ι) → Perm { a // f a = i }
a : α
⊢ ↑((Equiv.symm (g (f a))) ⟨stabilizerEquiv_invFun g a, ⋯⟩) = a
Module: Mathlib.GroupTheory.Perm.Cycle.PossibleTypes

Goal state before:
pp: case h
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
m : Multiset ℕ
hc : m.sum ≤ Fintype.card α
h2c : ∀ a ∈ m, 2 ≤ a
hc' : m.toList.sum ≤ Fintype.card α
p : List (List α)
hp_length : List.map List.length p = m.toList
hp_nodup : ∀ s ∈ p, s.Nodup
hp_disj : List.Pairwise List.Disjoint p
hp2 : ∀ x ∈ p, 2 ≤ x.length
x : List α
hx : x ∈ p
⊢ ((Finset.card ∘ support) ∘ fun l ↦ l.formPerm) x = x.length

Tactic:
simp only [Function.comp_apply]

Goal state after:
case h
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
m : Multiset ℕ
hc : m.sum ≤ Fintype.card α
h2c : ∀ a ∈ m, 2 ≤ a
hc' : m.toList.sum ≤ Fintype.card α
p : List (List α)
hp_length : List.map List.length p = m.toList
hp_nodup : ∀ s ∈ p, s.Nodup
hp_disj : List.Pairwise List.Disjoint p
hp2 : ∀ x ∈ p, 2 ≤ x.length
x : List α
hx : x ∈ p
⊢ x.formPerm.support.card = x.length
Module: Mathlib.GroupTheory.Perm.ClosureSwap

Goal state before:
pp: 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 ∉ s
hb' : ¬f b = b
⊢ b = a

Tactic:
simpa [hb] using supp_subset hb'

Goal state after:
Module: Mathlib.GroupTheory.PushoutI

Goal state before:
pp: case neg
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)
w : Word G
i : ι
h✝ : H
hw : ∀ (i : ι) (g : G i), ⟨i, g⟩ ∈ w.toList → ↑(⋯.equiv g).2 = g
hφw : ∀ (j : ι) (g : G j), ⟨j, g⟩ ∈ (CoprodI.of ((φ i) h✝) • w).toList → ↑(⋯.equiv g).2 = g
h : ¬∃ (h : w.toList ≠ []), (w.toList.head h).fst = i
⊢ ↑(⋯.equiv 1).2 = 1

Tactic:
rw [equiv_one (d.compl i) (one_mem _) (d.one_mem _)]

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

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

Tactic:
apply symm
    apply Nat.div_eq_of_eq_mul_left
    · have : 0 < m.prod := Multiset.prod_pos <| fun a ha => zero_lt_two.trans_le (hm.2 a ha)
      positivity
    rw [card_of_cycleType_mul_eq, if_pos hm]

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

Goal state before:
pp: α : Type u_1
inst✝¹ : Fintype α
inst✝ : DecidableEq α
g : Perm α
h : Subgroup.centralizer {g} ≤ alternatingGroup α
c : Perm α
hc : c ∈ g.cycleFactorsFinset
d : Perm α
hd : d ∈ g.cycleFactorsFinset
hm : #c.support = #d.support
hm' : c ≠ d
τ : Perm ↥g.cycleFactorsFinset := swap ⟨c, hc⟩ ⟨d, hd⟩
a : g.Basis
hτ : τ ∈ range_toPermHom' g
k : ↥(Subgroup.centralizer {g}) := a.toCentralizer ⟨τ, hτ⟩
hk : k = a.toCentralizer ⟨τ, hτ⟩
hk_cT : (↑k).cycleType = Multiset.replicate (↑k).cycleType.card 2
this : (↑k).cycleType.card * 2 = #(↑k).support
that : (↑k).cycleType.card = #c.support
⊢ (card ∘ support) c = #c.support

Tactic:
simp only [Function.comp_apply]

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
x✝ : (kleinFour α).Normal
⊢ Nat.card (↥(alternatingGroup α) ⧸ kleinFour α) = 3

Tactic:
← Nat.mul_left_inj (a := Nat.card (kleinFour α))

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
x✝ : (kleinFour α).Normal
⊢ Nat.card (↥(alternatingGroup α) ⧸ kleinFour α) * Nat.card ↥(kleinFour α) = 3 * Nat.card ↥(kleinFour α)

α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
x✝ : (kleinFour α).Normal
⊢ Nat.card ↥(kleinFour α) ≠ 0
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
⊢ IsPreprimitive ↥(alternatingGroup α) ↑(Set.powersetCard α 3)

Tactic:
refine Set.powersetCard.isPreprimitive_alternatingGroup (by norm_num) ?_ ?_

Goal state after:
case refine_1
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
⊢ 3 < Nat.card α

case refine_2
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
⊢ Nat.card α ≠ 2 * 3
Module: Mathlib.InformationTheory.Hamming

Goal state before:
pp: ι : Type u_2
β : ι → Type u_3
inst✝¹ : Fintype ι
inst✝ : (i : ι) → DecidableEq (β i)
x y z : (i : ι) → β i
⊢ hammingDist x y ≤ hammingDist x z + hammingDist y z

Tactic:
hammingDist_comm y

Goal state after:
ι : Type u_2
β : ι → Type u_3
inst✝¹ : Fintype ι
inst✝ : (i : ι) → DecidableEq (β i)
x y z : (i : ι) → β i
⊢ hammingDist x y ≤ hammingDist x z + hammingDist z y
Module: Mathlib.Probability.Kernel.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
f : β → ℝ≥0∞
g : α → β
a : α
hg : Measurable g
inst✝¹ : MeasurableSingletonClass β
s : Set β
inst✝ : Decidable (g a ∈ s)
⊢ ∫⁻ (x : β) in s, f x ∂(deterministic g hg) a = if g a ∈ s then f (g a) else 0

Tactic:
rw [deterministic_apply, setLIntegral_dirac f s]

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

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
⊢ κ.restrict ⋯ = κ

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
a : α
⊢ (κ.restrict ⋯) a = κ a
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✝ : Kernel α β
s t : Set β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
hs : MeasurableSet s
⊢ κ.restrict hs = Kernel.sum fun n ↦ (κ.seq n).restrict hs

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ✝ : Kernel α β
s t : Set β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
hs : MeasurableSet s
a : α
⊢ (κ.restrict hs) a = (Kernel.sum fun n ↦ (κ.seq n).restrict hs) 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
t : Set (α × β)
hκs : ∀ (a : α), IsFiniteMeasure (κ a)
t₁ : Set α
ht₁ : MeasurableSet t₁
t₂ : Set β
ht₂ : MeasurableSet t₂
⊢ (fun a ↦ (κ a) (if a ∈ t₁ then t₂ else ∅)) = fun a ↦ if a ∈ t₁ then (κ a) t₂ else 0

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
t : Set (α × β)
hκs : ∀ (a : α), IsFiniteMeasure (κ a)
t₁ : Set α
ht₁ : MeasurableSet t₁
t₂ : Set β
ht₂ : MeasurableSet t₂
a : α
⊢ (κ a) (if a ∈ t₁ then t₂ else ∅) = if a ∈ t₁ then (κ a) t₂ else 0
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✝ : Kernel α β
γ : Type u_4
mγ : MeasurableSpace γ
f : γ → β
κ : Kernel α β
hf : MeasurableEmbedding f
⊢ Measurable fun a ↦ Measure.comap f (κ a)

Tactic:
refine Measure.measurable_measure.mpr fun t ht => ?_

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ✝ : Kernel α β
γ : Type u_4
mγ : MeasurableSpace γ
f : γ → β
κ : Kernel α β
hf : MeasurableEmbedding f
t : Set γ
ht : MeasurableSet t
⊢ Measurable fun b ↦ (Measure.comap f (κ b)) t
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✝ : Kernel α β
γ : Type u_4
mγ : MeasurableSpace γ
f : γ → β
κ : Kernel α β
hf : MeasurableEmbedding f
t : Set γ
ht : MeasurableSet t
⊢ (fun a ↦ (Measure.comap f (κ a)) t) = fun a ↦ (κ a) (f '' t)

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ✝ : Kernel α β
γ : Type u_4
mγ : MeasurableSpace γ
f : γ → β
κ : Kernel α β
hf : MeasurableEmbedding f
t : Set γ
ht : MeasurableSet t
a : α
⊢ (Measure.comap f (κ a)) t = (κ a) (f '' t)
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
t✝ : Set (α × β)
hκs : ∀ (a : α), IsFiniteMeasure (κ a)
t : Set (α × β)
htm : MeasurableSet t
iht : Measurable fun a ↦ (κ a) (Prod.mk a ⁻¹' t)
h_eq_sdiff : ∀ (a : α), Prod.mk a ⁻¹' tᶜ = univ \ Prod.mk a ⁻¹' t
⊢ (fun a ↦ (κ a) (univ \ Prod.mk a ⁻¹' t)) = fun a ↦ (κ a) univ - (κ a) (Prod.mk a ⁻¹' t)

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
t✝ : Set (α × β)
hκs : ∀ (a : α), IsFiniteMeasure (κ a)
t : Set (α × β)
htm : MeasurableSet t
iht : Measurable fun a ↦ (κ a) (Prod.mk a ⁻¹' t)
h_eq_sdiff : ∀ (a : α), Prod.mk a ⁻¹' tᶜ = univ \ Prod.mk a ⁻¹' t
a : α
⊢ (κ a) (univ \ Prod.mk a ⁻¹' t) = (κ a) univ - (κ a) (Prod.mk a ⁻¹' t)
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✝ : Kernel α β
γ : Type u_4
mγ : MeasurableSpace γ
f : γ → β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
hf : MeasurableEmbedding f
⊢ κ.comapRight hf = Kernel.sum fun n ↦ (κ.seq n).comapRight hf

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ✝ : Kernel α β
γ : Type u_4
mγ : MeasurableSpace γ
f : γ → β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
hf : MeasurableEmbedding f
a : α
⊢ (κ.comapRight hf) a = (Kernel.sum fun n ↦ (κ.seq n).comapRight hf) a
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
⊢ piecewise hs κ η = Kernel.sum fun n ↦ piecewise hs (κ.seq n) (η.seq n)

Tactic:
ext1 a

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
⊢ (piecewise hs κ η) a = (Kernel.sum fun n ↦ piecewise hs (κ.seq n) (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
this : ∀ (a : α), ∫⁻ (b : β), ⨆ n, (F n) (a, b) ∂κ a = ⨆ n, ∫⁻ (b : β), (F n) (a, b) ∂κ a
n : ℕ
g₁ g₂ : SimpleFunc (α × β) ℝ≥0∞
a✝ : Disjoint (support ⇑g₁) (support ⇑g₂)
hm₁ : Measurable fun a ↦ ∫⁻ (b : β), g₁ (a, b) ∂κ a
hm₂ : Measurable fun a ↦ ∫⁻ (b : β), g₂ (a, b) ∂κ a
⊢ (fun a ↦ ∫⁻ (b : β), g₁ (a, b) + g₂ (a, b) ∂κ a) =
    (fun a ↦ ∫⁻ (b : β), g₁ (a, b) ∂κ a) + fun a ↦ ∫⁻ (b : β), g₂ (a, b) ∂κ a

Tactic:
ext1 a

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
n : ℕ
g₁ g₂ : SimpleFunc (α × β) ℝ≥0∞
a✝ : Disjoint (support ⇑g₁) (support ⇑g₂)
hm₁ : Measurable fun a ↦ ∫⁻ (b : β), g₁ (a, b) ∂κ a
hm₂ : Measurable fun a ↦ ∫⁻ (b : β), g₂ (a, b) ∂κ a
a : α
⊢ ∫⁻ (b : β), g₁ (a, b) + g₂ (a, b) ∂κ a = ((fun a ↦ ∫⁻ (b : β), g₁ (a, b) ∂κ a) + fun a ↦ ∫⁻ (b : β), g₂ (a, b) ∂κ a) a
Module: Mathlib.Probability.Kernel.MeasurableLIntegral

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
η : Kernel (α × β) γ
a : α
inst✝ : IsSFiniteKernel η
f : β × γ → ℝ≥0∞
hf : Measurable f
⊢ Measurable ((fun x ↦ ∫⁻ (y : γ), (fun u ↦ f (u.1.2, u.2)) (x, y) ∂η x) ∘ fun x ↦ (a, x))

Tactic:
refine (Measurable.lintegral_kernel_prod_right' (κ := η)
    (f := (fun u ↦ f (u.fst.snd, u.snd))) ?_).comp measurable_prodMk_left

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
η : Kernel (α × β) γ
a : α
inst✝ : IsSFiniteKernel η
f : β × γ → ℝ≥0∞
hf : Measurable f
⊢ Measurable fun u ↦ f (u.1.2, u.2)
Module: Mathlib.Probability.Kernel.Composition.MapComap

Goal state before:
pp: case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
γ : Type u_4
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
f : β → γ
hf : Measurable f
a : α
s : Set γ
hs : MeasurableSet s
⊢ ((Kernel.sum fun n ↦ (κ.seq n).map f) a) s = ((κ.map f) a) s

Tactic:
rw [Kernel.sum_apply, map_apply' κ hf a hs, Measure.sum_apply _ hs, ← measure_sum_seq κ,
      Measure.sum_apply _ (hf hs)]

Goal state after:
case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
γ : Type u_4
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
f : β → γ
hf : Measurable f
a : α
s : Set γ
hs : MeasurableSet s
⊢ ∑' (i : ℕ), (((κ.seq i).map f) a) s = ∑' (i : ℕ), ((κ.seq i) a) (f ⁻¹' s)
Module: Mathlib.Probability.Kernel.Composition.MeasureCompProd

Goal state before:
pp: case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ ν : Measure α
inst✝ : SFinite ν
hμν : μ ≪ ν
κ : Kernel α β
hκ : IsSFiniteKernel κ
⊢ μ ⊗ₘ κ ≪ ν ⊗ₘ κ

Tactic:
have : SFinite μ := sFinite_of_absolutelyContinuous hμν
    refine Measure.AbsolutelyContinuous.mk fun s hs hs_zero ↦ ?_
    rw [Measure.compProd_apply hs, lintegral_eq_zero_iff (Kernel.measurable_kernel_prodMk_left hs)]
      at hs_zero ⊢
    exact hμν.ae_eq hs_zero

Goal state after:
Module: Mathlib.Probability.Kernel.Composition.CompProd

Goal state before:
pp: case e'_3
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : MeasurableSingletonClass γ
f : α × β → γ
hf : Measurable f
s : Set (β × γ)
hs : MeasurableSet s
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
x : α
t : Set β := {b | (b, f (x, b)) ∈ s}
ht : MeasurableSet t
⊢ (κ x) {b | (b, f (x, b)) ∈ s} = ∫⁻ (x_1 : β) in t, if f (x, x_1) ∈ Prod.mk x_1 ⁻¹' s then 1 else 0 ∂κ x

Tactic:
suffices ∀ b ∈ t, (if f (x, b) ∈ Prod.mk b ⁻¹' s then (1 : ℝ≥0∞) else 0) = 1 by
      rw [setLIntegral_congr_fun ht this, setLIntegral_one]
    intro b hb
    simp only [t, Set.mem_ofPred_eq] at hb
    simp [hb]

Goal state after:
Module: Mathlib.Probability.Kernel.Composition.Prod

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
γ : Type u_4
δ : Type u_5
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
κ : Kernel α β
inst✝² : IsSFiniteKernel κ
η : Kernel α γ
inst✝¹ : IsSFiniteKernel η
ξ : Kernel α δ
inst✝ : IsSFiniteKernel ξ
⊢ (κ ×ₖ ξ ×ₖ η).map ⇑MeasurableEquiv.prodAssoc = κ ×ₖ (ξ ×ₖ η)

Tactic:
ext1 a

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
γ : Type u_4
δ : Type u_5
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
κ : Kernel α β
inst✝² : IsSFiniteKernel κ
η : Kernel α γ
inst✝¹ : IsSFiniteKernel η
ξ : Kernel α δ
inst✝ : IsSFiniteKernel ξ
a : α
⊢ ((κ ×ₖ ξ ×ₖ η).map ⇑MeasurableEquiv.prodAssoc) a = (κ ×ₖ (ξ ×ₖ η)) a
Module: Mathlib.Probability.Kernel.Composition.MeasureComp

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ : Kernel α β
inst✝¹ : Countable α
inst✝ : MeasurableSingletonClass α
⊢ ∀ᵐ (ω : α) ∂μ, κ ω ≪ ⇑κ ∘ₘ μ

Tactic:
rw [Measure.comp_eq_sum_of_countable, ae_iff_of_countable]

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ : Kernel α β
inst✝¹ : Countable α
inst✝ : MeasurableSingletonClass α
⊢ ∀ (x : α), μ {x} ≠ 0 → κ x ≪ sum fun ω ↦ μ {ω} • κ ω
Module: Mathlib.Probability.Kernel.MeasurableIntegral

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
E : Type u_4
inst✝² : NormedAddCommGroup E
inst✝¹ : IsSFiniteKernel κ
inst✝ : NormedSpace ℝ E
f : α × β → E
hf : StronglyMeasurable f
⊢ StronglyMeasurable fun x ↦ ∫ (y : β), f (x, y) ∂κ x

Tactic:
rw [← uncurry_curry f] at hf
  exact hf.integral_kernel_prod_right

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

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
E : Type u_4
inst✝² : NormedAddCommGroup E
inst✝¹ : IsSFiniteKernel κ
inst✝ : NormedSpace ℝ E
f : α × β → E
hf : StronglyMeasurable f
⊢ StronglyMeasurable fun x ↦ ∫ (y : β), f (x, y) ∂κ x

Tactic:
by
  rw [← uncurry_curry f] at hf
  exact hf.integral_kernel_prod_right

Goal state after: