∀ {Ω : Type u_1} {ι : Type u_2} {m : MeasurableSpace Ω} [inst : Preorder ι] {f : MeasureTheory.Filtration ι m}
  {β : ι → Type u_3} [inst_1 : (i : ι) → TopologicalSpace (β i)] {u v : (i : ι) → Ω → β i}
  [inst_2 : (i : ι) → Add (β i)] [∀ (i : ι), ContinuousAdd (β i)],
  MeasureTheory.StronglyAdapted f u → MeasureTheory.StronglyAdapted f v → MeasureTheory.StronglyAdapted f (u + v)