∀ {ι : Type u_1} {α : Type u_3} [inst : AddCommMonoid α] [inst_1 : Preorder α] [IsOrderedAddMonoid α]
  [inst_3 : TopologicalSpace α] [OrderClosedTopology α] {f : ι → α} {a : α},
  (∀ (i : ι), 0 ≤ f i) → HasSum f a → IsLUB (Set.range fun s => ∑ i ∈ s, f i) a