theorem
  (A*) |^ (m, n) c= A*
proof
  let x be object;
  assume x in (A*) |^ (m, n);
  then consider mn such that
  m <= mn and
  mn <= n and
A1: x in (A*) |^ mn by Th19;
  (A*) |^ mn c= A* by FLANG_1:65;
  hence thesis by A1;
end;
