theorem
  seq is bounded_above & seq1 is divergent_to+infty implies seq-seq1 is
  divergent_to-infty
proof
  assume that
A1: seq is bounded_above and
A2: seq1 is divergent_to+infty;
  (-jj)(#)seq1 is divergent_to-infty by A2,Th13;
  hence thesis by A1,Th12;
end;
