∀ {𝕜 : Type u_1} (E : Type u_2) [inst : NontriviallyNormedField 𝕜] [inst_1 : NormedRing E] [inst_2 : NormedAlgebra 𝕜 E]
  (c : ℕ → 𝕜) [NormOneClass E],
  Filter.Tendsto (fun n => ‖c n.succ‖ / ‖c n‖) Filter.atTop Filter.atTop →
    (FormalMultilinearSeries.ofScalars E c).radius = 0