theorem
  the carrier of Z_3 in UN & the addF of Z_3 in UN & comp Z_3 in UN &
0.Z_3
  in UN & the multF of Z_3 in UN & 1.Z_3 in UN
proof
  thus the carrier of Z_3 in UN by Lm8;
  hence thesis by Lm9,ORDINAL1:10;
end;
