∀ {α : Type u_1} {β : Type u_2} {𝕜 : Type u_3} [inst : TopologicalSpace α] [inst_1 : SeminormedAddCommGroup β]
  [inst_2 : NormedField 𝕜] [inst_3 : NormedSpace 𝕜 β] (c : 𝕜) (f : BoundedContinuousFunction α β), ‖c • f‖ ≤ ‖c‖ * ‖f‖