theorem
  n > 0 implies (A*) |^ n = A*
proof
  <%>E in A* by Th48;
  then
A1: n > 0 implies A* c= (A*) |^ n by Th35;
  (A*) |^ n c= A* by Th65;
  hence thesis by A1,XBOOLE_0:def 10;
end;
