theorem
  for z being Tuple of i+1,D ex t being Element of i-tuples_on D, d
   st z = t^<*d*>
proof
  let z be Tuple of i+1,D;
  consider t being Element of i-tuples_on D, s being Element of 1-tuples_on D
   such that
A1: z = t^s by Th104;
  ex d st s = <*d*> by Th95;
  hence thesis by A1;
end;
