theorem Th33:
  seq is convergent & lim seq = g implies ||.(seq + x) - (g + x)
  .|| is convergent & lim ||.(seq + x) - (g + x).|| = 0
proof
  assume seq is convergent & lim seq = g;
  then seq + x is convergent & lim (seq + x) = g + x by Th7,Th17;
  hence thesis by Th22;
end;
