∀ {ι : Type u_1} {M : Type u_3} {X : Type u_5} [inst : TopologicalSpace X] [inst_1 : TopologicalSpace M]
  [inst_2 : AddMonoid M] [ContinuousAdd M] {f : ι → X → M} (l : List ι),
  (∀ i ∈ l, Continuous (f i)) → Continuous fun a => (List.map (fun i => f i a) l).sum