theorem
  UBD [#]TOP-REAL n = {}TOP-REAL n
proof
  UBD [#]TOP-REAL n c= ([#]TOP-REAL n)` by JORDAN2C:26;
  then UBD [#]TOP-REAL n c= {}TOP-REAL n by XBOOLE_1:37;
  hence thesis by XBOOLE_1:3;
end;
