mathlib-initiative/mathlib-tactics huggingface dataset:
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
S : Subgroup (HNNExtension G A B φ) := { carrier := Set.ofPred motive, mul_mem' := ⋯, one_mem' := ⋯, inv_mem' := ⋯ }
⊢ motive x

Tactic:
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])

Goal state after:
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
S : Subgroup (HNNExtension G A B φ) := { carrier := Set.ofPred motive, mul_mem' := ⋯, one_mem' := ⋯, inv_mem' := ⋯ }
f : HNNExtension G A B φ →* ↥S := lift (HNNExtension.of.codRestrict S of) ⟨HNNExtension.t, t⟩ ⋯
⊢ motive x
Module: Mathlib.GroupTheory.HNNExtension

Goal state before:
pp: 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
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'
⊢ List.IsChain (fun a b ↦ a.2 ∈ toSubgroup A B a.1 → a.1 = b.1) ((u, w.head) :: w.toList)

Tactic:
by
      refine List.isChain_cons.2 ⟨?_, w.chain⟩
      rintro ⟨u', g'⟩ hu' hw1
      exact h2 _ (by simp_all) hw1

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
c : ↥g.cycleFactorsFinset
⊢ 1 • c = c

Tactic:
rw [← Subtype.coe_inj]
    change ConjAct.toConjAct (1 : Perm α) • c.val = c
    simp only [map_one, one_smul]

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

Goal state before:
pp: case pos
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
h1 : ¬f b = f a
h2 : f b = a
⊢ f a ∈ orbit (↥(closure S)) b

Tactic:
rw [← orbit_eq_iff.mpr (hf b), h2]

Goal state after:
case pos
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
h1 : ¬f b = f a
h2 : f b = a
⊢ f a ∈ orbit (↥(closure S)) a
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
i : ℕ
hi : i ∈ g.cycleType
⊢ Odd i

Tactic:
rw [cycleType_def g, Multiset.mem_map] at hi
  obtain ⟨c, hc, rfl⟩ := hi
  rw [← Finset.mem_def] at hc
  suffices sign c = 1 by
    rw [IsCycle.sign _, neg_eq_iff_eq_neg, ← Int.units_ne_iff_eq_neg] at this
    · rw [← Nat.not_even_iff_odd, comp_apply]
      exact fun h ↦ this h.neg_one_pow
    · rw [mem_cycleFactorsFinset_iff] at hc
      exact hc.left
  apply h
  rw [Subgroup.mem_centralizer_singleton_iff]
  exact Equiv.Perm.self_mem_cycle_factors_commute hc

Goal state after:
Module: Mathlib.GroupTheory.SchurZassenhaus

Goal state before:
pp: G : Type u_1
inst✝³ : Group G
H : Subgroup G
inst✝² : IsMulCommutative ↥H
inst✝¹ : H.FiniteIndex
α β : H.LeftTransversal
inst✝ : H.Normal
h : ↥H
⊢ diff (MonoidHom.id ↥H) α (op ↑h • β) = diff (MonoidHom.id ↥H) α β * h ^ H.index

Tactic:
let := H.fintypeQuotientOfFiniteIndex
  rw [diff, diff, index_eq_card, Nat.card_eq_fintype_card,
      ← Finset.card_univ, ← Finset.prod_const, ← Finset.prod_mul_distrib]
  refine Finset.prod_congr rfl fun q _ => ?_
  simp_rw [Subtype.ext_iff, MonoidHom.id_apply, coe_mul, mul_assoc, mul_right_inj]
  rw [smul_apply_eq_smul_apply_inv_smul, smul_eq_mul_unop, MulOpposite.unop_op, mul_left_inj,
    ← Subtype.ext_iff, Equiv.apply_eq_iff_eq, inv_smul_eq_iff]
  exact left_eq_mul.mpr ((QuotientGroup.eq_one_iff _).mpr h.2)

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
S : Sylow 2 ↥(alternatingGroup α)
⊢ Nat.card ↥(kleinFour α) = 4

Tactic:
← two_sylow_eq_kleinFour_of_card_eq_four hα4 S,

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
hα4 : Nat.card α = 4
S : Sylow 2 ↥(alternatingGroup α)
⊢ Nat.card ↥↑S = 4
Module: Mathlib.GroupTheory.SpecificGroups.ZGroup

Goal state before:
pp: G : Type u_1
G' : Type u_2
inst✝¹ : Group G
inst✝ : Group G'
f : G →* G'
hG' : ∀ (p : ℕ), Nat.Prime p → ∀ (P : Sylow p G'), IsCyclic ↥↑P
hf : Function.Injective ⇑f
p : ℕ
⊢ Nat.Prime p → ∀ (P : Sylow p G), IsCyclic ↥↑P

Tactic:
hp

Goal state after:
G : Type u_1
G' : Type u_2
inst✝¹ : Group G
inst✝ : Group G'
f : G →* G'
hG' : ∀ (p : ℕ), Nat.Prime p → ∀ (P : Sylow p G'), IsCyclic ↥↑P
hf : Function.Injective ⇑f
p : ℕ
hp : Nat.Prime p
⊢ ∀ (P : Sylow p G), IsCyclic ↥↑P
Module: Mathlib.GroupTheory.SpecificGroups.ZGroup

Goal state before:
pp: G : Type u_1
G' : Type u_2
inst✝² : Group G
inst✝¹ : Group G'
f : G →* G'
inst✝ : Finite G
hG : ∀ (p : ℕ), Nat.Prime p → ∀ (P : Sylow p G), IsCyclic ↥↑P
hf : Function.Surjective ⇑f
p : ℕ
⊢ Nat.Prime p → ∀ (P : Sylow p G'), IsCyclic ↥↑P

Tactic:
hp

Goal state after:
G : Type u_1
G' : Type u_2
inst✝² : Group G
inst✝¹ : Group G'
f : G →* G'
inst✝ : Finite G
hG : ∀ (p : ℕ), Nat.Prime p → ∀ (P : Sylow p G), IsCyclic ↥↑P
hf : Function.Surjective ⇑f
p : ℕ
hp : Nat.Prime p
⊢ ∀ (P : Sylow p G'), IsCyclic ↥↑P
Module: Mathlib.GroupTheory.SpecificGroups.ZGroup

Goal state before:
pp: G : Type u_1
G' : Type u_2
G'' : Type u_3
inst✝⁴ : Group G
inst✝³ : Group G'
inst✝² : Group G''
f : G →* G'
f' : G' →* G''
inst✝¹ : Finite G
inst✝ : IsZGroup G
H : Subgroup G
h : Nontrivial ↥H
⊢ ⁅⊤, ⊤⁆ < ⊤

Tactic:
exact commutator_lt H

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

Goal state before:
pp: G : Type u_1
inst✝² : Group G
inst✝¹ : Finite G
inst✝ : IsZGroup G
p : ℕ
⊢ Nat.Prime p → (Nat.card G).factorization p ≤ (Monoid.exponent G).factorization p

Tactic:
hp

Goal state after:
G : Type u_1
inst✝² : Group G
inst✝¹ : Finite G
inst✝ : IsZGroup G
p : ℕ
hp : Nat.Prime p
⊢ (Nat.card G).factorization p ≤ (Monoid.exponent G).factorization p
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
f : Perm α
hf : f.IsThreeCycle
⊢ normalClosure {⟨f, ⋯⟩} = ⊤

Tactic:
have : IsSimpleGroup (alternatingGroup α) := isSimpleGroup h5

Goal state after:
α : Type u_1
inst✝¹ : DecidableEq α
inst✝ : Fintype α
h5 : 5 ≤ Nat.card α
f : Perm α
hf : f.IsThreeCycle
this : IsSimpleGroup ↥(alternatingGroup α)
⊢ normalClosure {⟨f, ⋯⟩} = ⊤
Module: Mathlib.GroupTheory.SpecificGroups.ZGroup

Goal state before:
pp: case neg
G : Type u_1
inst✝⁴ : Group G
p : ℕ
inst✝³ : Fact (Nat.Prime p)
inst✝² : IsCyclic G
hG : IsPGroup p G
K : Type u_4
inst✝¹ : Group K
inst✝ : MulDistribMulAction K G
hGK : (Nat.card G).Coprime (Nat.card K)
hc : ¬Nat.card G = 0
this : Finite G
ϕ : K →* ZMod (Nat.card G) := MulDistribMulAction.toMonoidHomZModOfIsCyclic G K ⋯
⊢ (∀ (g : G) (k : K), k • g * g⁻¹ = 1) ∨ ∀ (g : G), ∃ k q, k • q * q⁻¹ = g

Tactic:
have h (g : G) (k : K) (n : ℤ) (h : ϕ k - 1 = n) : k • g * g⁻¹ = g ^ n := by
    rw [sub_eq_iff_eq_add, ← Int.cast_one, ← Int.cast_add] at h
    rw [MulDistribMulAction.toMonoidHomZModOfIsCyclic_apply rfl k g (n + 1) h,
      zpow_add_one, mul_inv_cancel_right]

Goal state after:
case neg
G : Type u_1
inst✝⁴ : Group G
p : ℕ
inst✝³ : Fact (Nat.Prime p)
inst✝² : IsCyclic G
hG : IsPGroup p G
K : Type u_4
inst✝¹ : Group K
inst✝ : MulDistribMulAction K G
hGK : (Nat.card G).Coprime (Nat.card K)
hc : ¬Nat.card G = 0
this : Finite G
ϕ : K →* ZMod (Nat.card G) := MulDistribMulAction.toMonoidHomZModOfIsCyclic G K ⋯
h : ∀ (g : G) (k : K) (n : ℤ), ϕ k - 1 = ↑n → k • g * g⁻¹ = g ^ n
⊢ (∀ (g : G) (k : K), k • g * g⁻¹ = 1) ∨ ∀ (g : G), ∃ k q, k • q * q⁻¹ = g
Module: Mathlib.GroupTheory.SpecificGroups.ZGroup

Goal state before:
pp: case refine_1
G : Type u_1
inst✝² : Group G
p : ℕ
inst✝¹ : Fact (Nat.Prime p)
P K : Subgroup G
inst✝ : IsCyclic ↥P
hP : IsPGroup p ↥P
hKP : K ≤ Subgroup.normalizer ↑P
hPK : (Nat.card ↥P).Coprime (Nat.card ↥K)
x✝ : MulDistribMulAction ↥K ↥P := MulDistribMulAction.compHom (↥P) (P.normalizerMonoidHom.comp (Subgroup.inclusion hKP))
h : ∀ (g : ↥P) (k : ↥K), k • g * g⁻¹ = 1
⊢ ∀ g₁ ∈ K, ∀ g₂ ∈ P, ⁅g₁, g₂⁆ ∈ ⊥

Tactic:
exact fun k hk g hg ↦ Subtype.ext_iff.mp (h ⟨g, hg⟩ ⟨k, hk⟩)

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

Goal state before:
pp: G : Type u_1
inst✝² : Group G
inst✝¹ : Finite G
inst✝ : IsZGroup G
p : ℕ
⊢ Nat.Prime p → ¬p ∣ Nat.card ↥(commutator G) ∨ ¬p ∣ (commutator G).index

Tactic:
hp

Goal state after:
G : Type u_1
inst✝² : Group G
inst✝¹ : Finite G
inst✝ : IsZGroup G
p : ℕ
hp : Nat.Prime p
⊢ ¬p ∣ Nat.card ↥(commutator G) ∨ ¬p ∣ (commutator G).index
Module: Mathlib.Probability.Kernel.Composition.Comp

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
κ : Kernel α β
η : Kernel β γ
a : α
s : Set γ
h : ((η ∘ₖ κ) a) s = 0
⊢ (fun x ↦ (η x) s) =ᵐ[κ a] 0

Tactic:
obtain ⟨t, hst, mt, ht⟩ := exists_measurable_superset_of_null h

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α β
η : Kernel β γ
a : α
s : Set γ
h : ((η ∘ₖ κ) a) s = 0
t : Set γ
hst : s ⊆ t
mt : MeasurableSet t
ht : ((η ∘ₖ κ) a) t = 0
⊢ (fun x ↦ (η x) s) =ᵐ[κ a] 0
Module: Mathlib.Probability.Kernel.Composition.ParallelComp

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : ι → Kernel α β
inst✝ : ∀ (i : ι), IsSFiniteKernel (κ i)
η : Kernel γ δ
h : ¬IsSFiniteKernel η
⊢ Kernel.sum κ ∥ₖ η = Kernel.sum fun i ↦ κ i ∥ₖ η

pp: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : ι → Kernel α β
inst✝ : ∀ (i : ι), IsSFiniteKernel (κ i)
η : Kernel γ δ
h : IsSFiniteKernel η
⊢ Kernel.sum κ ∥ₖ η = Kernel.sum fun i ↦ κ i ∥ₖ η

Tactic:
· simp [h]

Goal state after:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : ι → Kernel α β
inst✝ : ∀ (i : ι), IsSFiniteKernel (κ i)
η : Kernel γ δ
h : IsSFiniteKernel η
⊢ Kernel.sum κ ∥ₖ η = Kernel.sum fun i ↦ κ i ∥ₖ η
Module: Mathlib.Probability.Kernel.Composition.ParallelComp

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : Kernel α β
η : ι → Kernel γ δ
inst✝ : ∀ (i : ι), IsSFiniteKernel (η i)
h : ¬IsSFiniteKernel κ
⊢ κ ∥ₖ Kernel.sum η = Kernel.sum fun i ↦ κ ∥ₖ η i

pp: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : Kernel α β
η : ι → Kernel γ δ
inst✝ : ∀ (i : ι), IsSFiniteKernel (η i)
h : IsSFiniteKernel κ
⊢ κ ∥ₖ Kernel.sum η = Kernel.sum fun i ↦ κ ∥ₖ η i

Tactic:
· simp [h]

Goal state after:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : Kernel α β
η : ι → Kernel γ δ
inst✝ : ∀ (i : ι), IsSFiniteKernel (η i)
h : IsSFiniteKernel κ
⊢ κ ∥ₖ Kernel.sum η = Kernel.sum fun i ↦ κ ∥ₖ η i
Module: Mathlib.Probability.Kernel.Composition.ParallelComp

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
mδ : MeasurableSpace δ
ι : Type u_5
inst✝¹ : Countable ι
κ : Kernel α β
η : ι → Kernel γ δ
inst✝ : ∀ (i : ι), IsSFiniteKernel (η i)
⊢ κ ∥ₖ Kernel.sum η = Kernel.sum fun i ↦ κ ∥ₖ η i

Tactic:
by_cases h : IsSFiniteKernel κ
  swap; · simp [h]
  ext x
  simp_rw [Kernel.sum_apply, parallelComp_apply, Kernel.sum_apply, Measure.prod_sum_right]

Goal state after:
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✝¹ : SFinite μ
inst✝ : SFinite ν
κ : Kernel α β
hκ : IsSFiniteKernel κ
⊢ (μ + ν) ⊗ₘ κ = μ ⊗ₘ κ + ν ⊗ₘ κ

Tactic:
simp_rw [Measure.compProd, Kernel.const_add, Kernel.compProd_add_left, _root_.add_apply]

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

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ η : Kernel α β
inst✝¹ : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
hμ : ¬SFinite μ
⊢ μ ⊗ₘ (κ + η) = μ ⊗ₘ κ + μ ⊗ₘ η

Tactic:
· simp [hμ]

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

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
δ : Type u_4
mδ : MeasurableSpace δ
κ : Kernel α β
inst✝ : IsMarkovKernel κ
⊢ IsMarkovKernel (Kernel.prodMkRight γ κ)

Tactic:
rw [Kernel.prodMkRight]; infer_instance

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

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
δ : Type u_4
mδ : MeasurableSpace δ
κ : Kernel α β
inst✝ : IsZeroOrMarkovKernel κ
⊢ IsZeroOrMarkovKernel (Kernel.prodMkRight γ κ)

Tactic:
rw [Kernel.prodMkRight]; infer_instance

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

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
δ : Type u_4
mδ : MeasurableSpace δ
κ : Kernel α β
inst✝ : IsFiniteKernel κ
⊢ IsFiniteKernel (Kernel.prodMkRight γ κ)

Tactic:
rw [Kernel.prodMkRight]; infer_instance

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

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
δ : Type u_4
mδ : MeasurableSpace δ
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
⊢ IsSFiniteKernel (Kernel.prodMkRight γ κ)

Tactic:
rw [Kernel.prodMkRight]; infer_instance

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

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
κ : Kernel α (β × γ)
a : α
g : γ × β → ℝ≥0∞
hg : Measurable g
⊢ ∫⁻ (c : γ × β), g c ∂(κ.map Prod.swap) a = ∫⁻ (bc : β × γ), g bc.swap ∂κ a

Tactic:
lintegral_map _ measurable_swap a hg

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α (β × γ)
a : α
g : γ × β → ℝ≥0∞
hg : Measurable g
⊢ ∫⁻ (a : β × γ), g a.swap ∂κ a = ∫⁻ (bc : β × γ), g bc.swap ∂κ a
Module: Mathlib.Probability.Kernel.Composition.MeasureCompProd

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ : Kernel α β
γ : Type u_3
mγ : MeasurableSpace γ
η : Kernel (α × β) γ
hμ : ¬SFinite μ
⊢ map (⇑MeasurableEquiv.prodAssoc.symm) (μ ⊗ₘ (κ ⊗ₖ η)) = μ ⊗ₘ κ ⊗ₘ η

pp: case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ : Kernel α β
γ : Type u_3
mγ : MeasurableSpace γ
η : Kernel (α × β) γ
hμ : SFinite μ
⊢ map (⇑MeasurableEquiv.prodAssoc.symm) (μ ⊗ₘ (κ ⊗ₖ η)) = μ ⊗ₘ κ ⊗ₘ η

Tactic:
· simp [hμ]

Goal state after:
case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ : Kernel α β
γ : Type u_3
mγ : MeasurableSpace γ
η : Kernel (α × β) γ
hμ : SFinite μ
⊢ map (⇑MeasurableEquiv.prodAssoc.symm) (μ ⊗ₘ (κ ⊗ₖ η)) = μ ⊗ₘ κ ⊗ₘ η
Module: Mathlib.Probability.Kernel.Composition.CompProd

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
s : Set (β × γ)
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
a : α
h : ((κ ⊗ₖ η) a) s = 0
⊢ (fun b ↦ (η (a, b)) (Prod.mk b ⁻¹' s)) =ᵐ[κ a] 0

Tactic:
obtain ⟨t, hst, mt, ht⟩ := exists_measurable_superset_of_null h

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
s : Set (β × γ)
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
a : α
h : ((κ ⊗ₖ η) a) s = 0
t : Set (β × γ)
hst : s ⊆ t
mt : MeasurableSet t
ht : ((κ ⊗ₖ η) a) t = 0
⊢ (fun b ↦ (η (a, b)) (Prod.mk b ⁻¹' s)) =ᵐ[κ a] 0
Module: Mathlib.Probability.Kernel.Composition.CompProd

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
a : α
κ : Kernel α β
η : Kernel (α × β) γ
p : β × γ → Prop
hp : MeasurableSet {x | p x}
h : ∀ᵐ (b : β) ∂κ a, ∀ᵐ (c : γ) ∂η (a, b), p (b, c)
hκ : ¬IsSFiniteKernel κ
⊢ ∀ᵐ (bc : β × γ) ∂(κ ⊗ₖ η) a, p bc

pp: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
a : α
κ : Kernel α β
η : Kernel (α × β) γ
p : β × γ → Prop
hp : MeasurableSet {x | p x}
h : ∀ᵐ (b : β) ∂κ a, ∀ᵐ (c : γ) ∂η (a, b), p (b, c)
hκ : IsSFiniteKernel κ
⊢ ∀ᵐ (bc : β × γ) ∂(κ ⊗ₖ η) a, p bc

Tactic:
· simp [compProd_of_not_isSFiniteKernel_left _ _ hκ]

Goal state after:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
a : α
κ : Kernel α β
η : Kernel (α × β) γ
p : β × γ → Prop
hp : MeasurableSet {x | p x}
h : ∀ᵐ (b : β) ∂κ a, ∀ᵐ (c : γ) ∂η (a, b), p (b, c)
hκ : IsSFiniteKernel κ
⊢ ∀ᵐ (bc : β × γ) ∂(κ ⊗ₖ η) a, p bc
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
a : ℝ≥0∞
⊢ ⇑κ ∘ₘ (a • μ) = a • ⇑κ ∘ₘ μ

Tactic:
ext s hs
  simp only [bind_apply hs κ.aemeasurable, lintegral_smul_measure, smul_apply, smul_eq_mul]

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

Goal state before:
pp: case pos.refine_1
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
E : Type u_4
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : β → E
hf : StronglyMeasurable f
hE : CompleteSpace E
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : TopologicalSpace.SeparableSpace ↑(range f ∪ {0})
s : ℕ → SimpleFunc β E := SimpleFunc.approxOn f ⋯ (range f ∪ {0}) 0 ⋯
f' : ℕ → α → E := fun n ↦ {x | Integrable f (κ x)}.indicator fun x ↦ SimpleFunc.integral (κ x) (s n)
n : ℕ
⊢ StronglyMeasurable (f' n)

pp: case pos.refine_2
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
E : Type u_4
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : β → E
hf : StronglyMeasurable f
hE : CompleteSpace E
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : TopologicalSpace.SeparableSpace ↑(range f ∪ {0})
s : ℕ → SimpleFunc β E := SimpleFunc.approxOn f ⋯ (range f ∪ {0}) 0 ⋯
f' : ℕ → α → E := fun n ↦ {x | Integrable f (κ x)}.indicator fun x ↦ SimpleFunc.integral (κ x) (s n)
⊢ Tendsto f' atTop (𝓝 fun x ↦ ∫ (y : β), f y ∂κ x)

Tactic:
· refine StronglyMeasurable.indicator ?_ (measurableSet_integrable hf)
    simp_rw [SimpleFunc.integral_eq]
    refine Finset.stronglyMeasurable_fun_sum _ fun _ _ ↦ ?_
    refine (Measurable.ennreal_toReal ?_).stronglyMeasurable.smul_const _
    exact κ.measurable_coe ((s n).measurableSet_fiber _)

Goal state after:
case pos.refine_2
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
E : Type u_4
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
f : β → E
hf : StronglyMeasurable f
hE : CompleteSpace E
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : TopologicalSpace.SeparableSpace ↑(range f ∪ {0})
s : ℕ → SimpleFunc β E := SimpleFunc.approxOn f ⋯ (range f ∪ {0}) 0 ⋯
f' : ℕ → α → E := fun n ↦ {x | Integrable f (κ x)}.indicator fun x ↦ SimpleFunc.integral (κ x) (s n)
⊢ Tendsto f' atTop (𝓝 fun x ↦ ∫ (y : β), f y ∂κ x)
Module: Mathlib.Probability.Kernel.Composition.CompProd

Goal state before:
pp: case hf
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
a : α
f : β × γ → ℝ≥0∞
hf : Measurable f
g : β → γ → ℝ≥0∞ := Function.curry f
⊢ Measurable (Function.uncurry g)

Tactic:
· simp_rw [g, Function.uncurry_curry]; exact hf

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

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ η : Kernel α β
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : IsFiniteKernel η
h_ac : μ ⊗ₘ κ ≪ μ ⊗ₘ η
ν : Measure α
inst✝ : IsFiniteMeasure ν
p : α × β
⊢ (μ ⊗ₘ η).rnDeriv (ν ⊗ₘ η) p = μ.rnDeriv ν p.1 →
    ((μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) * (μ ⊗ₘ η).rnDeriv (ν ⊗ₘ η)) p = μ.rnDeriv ν p.1 * (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) p

Tactic:
hp

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ η : Kernel α β
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : IsFiniteKernel η
h_ac : μ ⊗ₘ κ ≪ μ ⊗ₘ η
ν : Measure α
inst✝ : IsFiniteMeasure ν
p : α × β
hp : (μ ⊗ₘ η).rnDeriv (ν ⊗ₘ η) p = μ.rnDeriv ν p.1
⊢ ((μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) * (μ ⊗ₘ η).rnDeriv (ν ⊗ₘ η)) p = μ.rnDeriv ν p.1 * (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) p
Module: Mathlib.Probability.Kernel.Composition.CompProd

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
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
a : α
f : β × γ → ℝ≥0∞
hf : AEMeasurable f ((κ ⊗ₖ η) a)
⊢ ∫⁻ (z : β × γ), f z ∂(κ ⊗ₖ η) a = ∫⁻ (x : β), ∫⁻ (y : γ), f (x, y) ∂η (a, x) ∂κ a

Tactic:
have A : ∫⁻ z, f z ∂(κ ⊗ₖ η) a = ∫⁻ z, hf.mk f z ∂(κ ⊗ₖ η) a := lintegral_congr_ae hf.ae_eq_mk
  have B : ∫⁻ x, ∫⁻ y, f (x, y) ∂η (a, x) ∂κ a = ∫⁻ x, ∫⁻ y, hf.mk f (x, y) ∂η (a, x) ∂κ a := by
    apply lintegral_congr_ae
    filter_upwards [ae_ae_of_ae_compProd hf.ae_eq_mk] with _ ha using lintegral_congr_ae ha
  rw [A, B, lintegral_compProd]
  exact hf.measurable_mk

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Tilted

Goal state before:
pp: case neg
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
g : α → ℝ≥0∞
s : Set α
hs : MeasurableSet s
hf : ¬AEMeasurable f μ
⊢ ∫⁻ (x : α) in s, g x ∂μ.tilted f = ∫⁻ (x : α) in s, ENNReal.ofReal (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) * g x ∂μ

Tactic:
· have hf' : ¬ Integrable (fun x ↦ exp (f x)) μ := by
      exact fun h ↦ hf (aemeasurable_of_aemeasurable_exp h.1.aemeasurable)
    simp only [hf, not_false_eq_true, tilted_of_not_aemeasurable, Measure.restrict_zero,
      lintegral_zero_measure]
    rw [integral_undef hf']
    simp

Goal state after: