anyonyaparihārasthitalakṣaṇayoścaikapratiṣedhasyāparavidhināntarīyakatvād ityabhāvaḥ svayaṃ siddhyatīti bhāvaḥ /
Since these two [positions] are characterized by mutual exclusion, and the negation of one necessarily involves the affirmation of the other, therefore the negative [position] is established by itself - this is the meaning.