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

theorem Th94:
  for o,m being set st not (m is U-set) or not (o is U-set) holds
  not 1Cat(o,m) is U-small
  proof
    let o,m be set;
    assume not m is U-set or not o is U-set;
    then per cases;
    suppose
A1:   not m is U-set;
      1Cat( o,m) = CatStr(# {o},{m},m:->o,m:->o,(m,m):->m #) by CAT_1:def 11;
      hence thesis by A1,Th18;
    end;
    suppose
A2:   not o is U-set;
      1Cat( o,m) = CatStr(# {o},{m},m:->o,m:->o,(m,m):->m #) by CAT_1:def 11;
      hence thesis by A2,Th18;
    end;
  end;
