∀ {G : Type u_1} [inst : NormedAddCommGroup G] [CompleteSpace G] {H : Type u_2} [inst_2 : NormedAddCommGroup H]
  {f : NormedAddGroupHom G H} {K : AddSubgroup H} {C ε : ℝ},
  0 < C → 0 < ε → f.SurjectiveOnWith K C → f.SurjectiveOnWith K.topologicalClosure (C + ε)