theorem Th25:
  for f be Element of MSAAut U1 holds f"" in MSAAut U1
proof
  let f be Element of MSAAut U1;
  f is_isomorphism U1, U1 by Def5;
  then f"" is_isomorphism U1, U1 by MSUALG_3:14;
  hence thesis by Def5;
end;
