∀ {α : Type u_1} {f : ℤ → α} [inst : AddCommGroup α] [inst_1 : TopologicalSpace α] [ContinuousAdd α],
  Summable f (SummationFilter.symmetricIcc ℤ) →
    Filter.Tendsto (fun N => -f ↑N) Filter.atTop (nhds 0) → Summable f (SummationFilter.symmetricIco ℤ)