The Bhikṣuṇī Maṇimēkhalai

282 - Buddhist Logic
While this may be regarded as valid in so far as it applies to the pot,
etc., which are homogeneous as being products of effort, sound is
eternal because it is audible as is the character of sound, is also
equally valid. Since the validity is equally good for both the thesis and
its contradictory, it ceases to be Aikāntika (peculiar).
Viruddha is of four kinds, namely:–
(1) Dharmasvarūpaviparītasādhanam: where in the statement of the
Pakṣa or Dharmin, the major term is contradictory to the Sādhana or
the middle term; [214]
(2) Dharmaviśēṣaviparītasādhanam: where the Dharmaviśēṣa or the
attribute or the predicate implied in the major term is contradictory
to the middle term, Sādhana;
(3) Dharmasvarūpaviparītasādhanam: where the form of the minor
term is contradictory to the Sādhana or the middle term; and
(4) Dharmaviśēṣaviparitasādhanam: when the predicate implied in
the minor term is contradictory to the Sādhanam or the middle term.
Of these the first is found when in the hētu, the middle term, the
major term is faulty, as in the example:
Sound is eternal
Because it is a product.
In this the character of being a product implies that sound is
non-eternal. Therefore the hētu or reason of being a product
establishes the non-eternality which is contradictory to the eternality
stated in the middle term. Hence the contradiction between the two.