-- Mathlib/MeasureTheory/VectorMeasure/Basic.lean
theorem restrict_le_restrict_iUnion {f : ℕ → Set α} (hf₁ : ∀ n, MeasurableSet (f n))
    (hf₂ : ∀ n, v ≤[f n] w) : v ≤[⋃ n, f n] w

Proof state:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ ↑v a ≤ ↑w a

Tactic:
rw [← ha₃, v.of_disjoint_iUnion _ ha₄, w.of_disjoint_iUnion _ ha₄]

Result:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ ∑' (i : ℕ), ↑v (a ∩ disjointed f i) ≤ ∑' (i : ℕ), ↑w (a ∩ disjointed f i)

α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ ∀ (i : ℕ), MeasurableSet (a ∩ disjointed f i)

α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ ∀ (i : ℕ), MeasurableSet (a ∩ disjointed f i)

Proof state:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ ∀ (i : ℕ), MeasurableSet (a ∩ disjointed f i)

Tactic:
exact fun n => ha₁.inter (MeasurableSet.disjointed hf₁ n)

Result:
no goals

Proof state:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
n : ℕ
⊢ MeasurableSet (a ∩ disjointed f n)

Tactic:
exact ha₁.inter (MeasurableSet.disjointed hf₁ n)

Result:
no goals

Proof state:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
⊢ v ≤[⋃ n, f n] w

Tactic:
refine restrict_le_restrict_of_subset_le v w fun a ha₁ ha₂ => ?_

Result:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
⊢ ↑v a ≤ ↑w a

Proof state:
case refine_4
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ Summable fun i => ↑w (a ∩ disjointed f i)

Tactic:
refine (w.m_iUnion (fun n => ?_) ?_).summable

Result:
case refine_4.refine_1
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
n : ℕ
⊢ MeasurableSet (a ∩ disjointed f n)

case refine_4.refine_2
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ Pairwise (Disjoint on fun i => a ∩ disjointed f i)

Proof state:
case refine_4.refine_2
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
⊢ Pairwise (Disjoint on fun i => a ∩ disjointed f i)

Tactic:
exact (disjoint_disjointed _).mono fun i j => Disjoint.mono inf_le_right inf_le_right

Result:
no goals

Proof state:
case refine_4.refine_1
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
n : ℕ
⊢ MeasurableSet (a ∩ disjointed f n)

Tactic:
exact ha₁.inter (MeasurableSet.disjointed hf₁ n)

Result:
no goals

Proof state:
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
⊢ ⋃ n, a ∩ disjointed f n = a

Tactic:
rwa [← Set.inter_iUnion, iUnion_disjointed, Set.inter_eq_left]

Result:
no goals

Proof state:
case refine_3.refine_1
α : Type u_1
m : MeasurableSpace α
M : Type u_3
inst✝² : TopologicalSpace M
inst✝¹ : OrderedAddCommMonoid M
inst✝ : OrderClosedTopology M
v w : VectorMeasure α M
f : ℕ → Set α
hf₁ : ∀ (n : ℕ), MeasurableSet (f n)
hf₂ : ∀ (n : ℕ), v ≤[f n] w
a : Set α
ha₁ : MeasurableSet a
ha₂ : a ⊆ ⋃ n, f n
ha₃ : ⋃ n, a ∩ disjointed f n = a
ha₄ : Pairwise (Disjoint on fun n => a ∩ disjointed f n)
n : ℕ
⊢ MeasurableSet (a ∩ disjointed f n)

Tactic:
exact ha₁.inter (MeasurableSet.disjointed hf₁ n)

Result:
no goals