The Bhikṣuṇī Maṇimēkhalai

275 - Buddhist Logic
In negative pramāṇa the statement that in this open space there is no
pot constitutes the subject. ‘Because it is not seen’, is the attribute of
the subject. ‘As they do not exist, we have not seen the horns of a
rabbit’, is a similar example of that method. When we say ‘whatever
exists will be seen like a myrabolam in the open hand’ is a similar but
counter-statement. It is in this way that what is urged as reason
establishes facts.
If you ask what it is that smoke (as reason) establishes, the existence
of smoke proves the existence of fire by the positive concomitance,
where there is smoke there is always fire, and the negative
concomitance there is no smoke where there is no fire. If so, when one
sees before him smoke, the darkness proceeding straight from it, or
going up in spiral, as this is due to fire, when you see something dark
and smoky overhead you must infer the existence of fire. If
co-existence thus establishes facts, then when one who had formerly
seen an ass and a woman at one place and at one time, sees an ass at
another time, he should infer the existence of a woman then and there.
No. This will not do.
If the negative concomitance will prove that there is no smoke where
there is no fire, one who did not see in the mane of an ass the tail of a
fox because he saw no tail of a dog, could rarely infer the existence of
a dog’s tail in another place where he saw the tail of a fox. Therefore
even that is inadmissible. Upanaya (application) and nigamana
(conclusion), connected with the (example) as they are, may
be regarded as included in it.
Pakṣa (proposition), hētu (reason), (example) are of two
kinds, valid and invalid. Among [208] these, the valid proposition is
that which has included in it (1) the explicit subject possessed of
attributes, and (2) the changes that the plainly discernible attribute of
the conclusion undergoes when found elsewhere.