
theorem
  for X be RealNormSpace for seq be sequence of X holds (for n be
  Nat holds ||.seq.||.n>0) & (ex m be Nat st for n be
 Nat st n >=m holds ||.seq.||.(n+1)/||.seq.||.n >= 1) implies not seq
  is norm_summable by SERIES_1:27;
