
theorem Th38:
  for P, Q being non empty pcs-Str, p, q being Element of P pcs-times Q
  for p1, p2 being Element of P, q1, q2 being Element of Q st
  p = [p1,q1] & q = [p2,q2] holds p1 (--) p2 or q1 (--) q2 implies p (--) q
by Def2;
