∀ {Ω : Type u_1} {ι : Type u_2} {x : MeasurableSpace Ω} {μ : MeasureTheory.Measure Ω} [Subsingleton ι]
  {β : ι → Type u_7} {m : (i : ι) → MeasurableSpace (β i)} {f : (i : ι) → Ω → β i}
  [MeasureTheory.IsProbabilityMeasure μ], ProbabilityTheory.iIndepFun f μ = True