∀ {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} [Countable β] {f : β → Set α} {M : Type u_4}
  [inst : TopologicalSpace M] [inst_1 : AddCommMonoid M] [inst_2 : PartialOrder M] [IsOrderedAddMonoid M]
  [OrderClosedTopology M] {v : MeasureTheory.VectorMeasure α M},
  (∀ (i : β), MeasurableSet (f i)) →
    Pairwise (Function.onFun Disjoint f) → (∀ (i : β), ↑v (f i) ≤ 0) → ↑v (⋃ i, f i) ≤ 0