reserve U for Universe;
reserve x for Element of U;
reserve U1,U2 for Universe;

theorem
  for o,m being object st 1Cat(o,m) is U-small holds m is U-set &
  o is U-set
  proof
    let o,m be object;
    reconsider o9=o,m9=m as set by TARSKI:1;
    assume 1Cat(o,m) is U-small;
    then 1Cat(o9,m9) is U-small;
    hence thesis by Th94;
end;
