∀ {E : Type u_5} [inst : Ring E] [inst_1 : UniformSpace E] [IsUniformAddGroup E] [CompleteSpace E] {f : ℕ → E},
  Summable f →
    Filter.Tendsto (fun n => ∑ i ∈ Finset.range n, (-1) ^ i * f i) Filter.atTop (nhds (∑' (i : ℕ), (-1) ^ i * f i))