 reserve n,m for Nat,
      o for object,
      p for pair object,
      x,y,z for Surreal;

theorem
  Union sqrtL(p,o) = {} implies L_p={}
proof
  assume Union sqrtL(p,o) = {};
  then sqrtL(p,o).0 c= {} by ABCMIZ_1:1;
  hence thesis by Th6;
end;
