theorem Th5:
  for p, q being XFinSequence holds a = p ^ q implies p is Element
  of E^omega & q is Element of E^omega
proof
  let p, q be XFinSequence;
  assume a = p ^ q;
  then p is XFinSequence of E & q is XFinSequence of E by AFINSQ_1:31;
  hence thesis by AFINSQ_1:def 7;
end;
