Note 515 — Chapter V
Reading edition
Thus the rule for elimination from particular negatives is practically identical with the rule for elimination from universal negatives. The same rule may be deduced by obversion from the result obtained in the preceding section. Something is not either PX or Qx or R ; therefore, Something is either prX or qrx or pqr ; therefore, Something is either pr or qr ; therefore, Something is not either PQ or R.