exact (hX.aemeasurable a).nullMeasurableSet_preimage MeasurableSpace.measurableSet_top
α : Type u_1
Ω : Type u_2
inst✝ : MeasurableSpace Ω
X Y : Ω → Set α
μ : Measure Ω
p q : ℝ≥0
hX : IsBernoulliSeq X p μ
hY : IsBernoulliSeq Y q μ
a : α
⊢ NullMeasurableSet ((fun ω => a ∈ X ω) ⁻¹' {True}) μ
no goals