∀ {α : Type u_1} {β : Type u_2} {ι : Type u_3} [inst : AddCommMonoid α] {f : ι → β → α} {g : β → α} {s : Set β}
  [inst_1 : UniformSpace α] [T2Space α], HasSumUniformlyOn f g s → Set.EqOn (fun x => ∑' (b : ι), f b x) g s