∀ {α : Type u_1} {β : Type u_2} [inst : CommMonoid α] [inst_1 : TopologicalSpace α] [inst_2 : Unique β] (f : β → α)
  (L : optParam (SummationFilter β) (SummationFilter.unconditional β)) [L.LeAtTop], HasProd f (f default) L = True