theorem
  seq is convergent & lim seq = g implies dist((seq + x) , (g + x)) is
  convergent & lim dist((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 Th24;
end;
