α : Type u_1
inst✝ : MeasurableSpace α
μ : MeasureTheory.Measure α
f g : α → ℝ
s : Set α
hf : Measurable f
hg : Measurable g
hs : MeasurableSet s
⊢ MeasurableSet ({a | a.fst ∈ s} ∩ {a | a.snd ∈ {a_1 | f a.fst ≤ a_1} ∩ {a_1 | a_1 ≤ g a.fst}})
α : Type u_1
inst✝ : MeasurableSpace α
μ : MeasureTheory.Measure α
f g : α → ℝ
s : Set α
hf : Measurable f
hg : Measurable g
hs : MeasurableSet s
⊢ MeasurableSet {p | p.fst ∈ s ∧ p.snd ∈ Icc (f p.fst) (g p.fst)}
dsimp only [regionBetween, Icc, mem_setOf_eq, setOf_and]
α : Type u_1
inst✝ : MeasurableSpace α
μ : MeasureTheory.Measure α
f g : α → ℝ
s : Set α
hf : Measurable f
hg : Measurable g
hs : MeasurableSet s
⊢ MeasurableSet {a | a.fst ∈ s}
α : Type u_1
inst✝ : MeasurableSpace α
μ : MeasureTheory.Measure α
f g : α → ℝ
s : Set α
hf : Measurable f
hg : Measurable g
hs : MeasurableSet s
⊢ MeasurableSet ({a | a.fst ∈ s} ∩ {a | a.snd ∈ {a_1 | f a.fst ≤ a_1} ∩ {a_1 | a_1 ≤ g a.fst}})
refine'
  MeasurableSet.inter _
    ((measurableSet_le (hf.comp measurable_fst) measurable_snd).inter
      (measurableSet_le measurable_snd (hg.comp measurable_fst)))
no goals
α : Type u_1
inst✝ : MeasurableSpace α
μ : MeasureTheory.Measure α
f g : α → ℝ
s : Set α
hf : Measurable f
hg : Measurable g
hs : MeasurableSet s
⊢ MeasurableSet {a | a.fst ∈ s}
exact measurable_fst hs