α : Type u_2
β : Type u_1
γ : Type ?u.37295
δ : Type ?u.37298
ι : Type ?u.37301
R : Type ?u.37304
R' : Type ?u.37307
m : MeasurableSpace α
μ μ₁ μ₂ : Measure α
s✝ s₁ s₂ t : Set α
I : Set β
hc : Set.Countable I
s : β → Set α
this : Encodable ↑I
⊢ ↑↑μ (⋃ (b : β) (_ : b ∈ I), toMeasurable μ (s b)) = ↑↑μ (⋃ (b : β) (_ : b ∈ I), s b)
α : Type u_2
β : Type u_1
γ : Type ?u.37295
δ : Type ?u.37298
ι : Type ?u.37301
R : Type ?u.37304
R' : Type ?u.37307
m : MeasurableSpace α
μ μ₁ μ₂ : Measure α
s✝ s₁ s₂ t : Set α
I : Set β
hc : Set.Countable I
s : β → Set α
⊢ ↑↑μ (⋃ (b : β) (_ : b ∈ I), toMeasurable μ (s b)) = ↑↑μ (⋃ (b : β) (_ : b ∈ I), s b)
haveI := hc.toEncodable
no goals
α : Type u_2
β : Type u_1
γ : Type ?u.37295
δ : Type ?u.37298
ι : Type ?u.37301
R : Type ?u.37304
R' : Type ?u.37307
m : MeasurableSpace α
μ μ₁ μ₂ : Measure α
s✝ s₁ s₂ t : Set α
I : Set β
hc : Set.Countable I
s : β → Set α
this : Encodable ↑I
⊢ ↑↑μ (⋃ (b : β) (_ : b ∈ I), toMeasurable μ (s b)) = ↑↑μ (⋃ (b : β) (_ : b ∈ I), s b)
simp only [biUnion_eq_iUnion, measure_iUnion_toMeasurable]