∀ {α : Type u_1} {ι : Type u_4} {mα : MeasurableSpace α} {ν : MeasureTheory.Measure α}
  {μs : ι → MeasureTheory.Measure α} (i : ι),
  ν.AbsolutelyContinuous (μs i) → ν.AbsolutelyContinuous (MeasureTheory.Measure.sum μs)