Contradictory sign in the proof of that

སྒྲ་རྟག་པར་སྒྲུབ་པའི་ཕྱོགས་ཆོས་ཀྱང་ཡིན། སྒྲ་རྟག་པར་མ་ཡིན་པར་སྒྲུབ་པའི་རྗེས་ཁྱབ་ཀྱང་ཡིན་པའི་གཞི་མཐུན་པ་དེ།
སྒྲ་རྟག་པར་སྒྲུབ་པའི་འགལ་རྟགས་ཀྱི་མཚན་ཉིད།
Definition of contradictory sign in the proof of sound as permanent:
That which is a common locus between:

1. being the property of the subject in the proof that sound is permanent and
2. being the forward pervasion in the proof that sound is not permanent.

Illustrations: Sound is permanent because of being a product / instance of product.

Divisions:

1. Contradictory sign that pervades the discordant class
   མི་མཐུན་ཕྱོགས་ལ་ཁྱབ་བྱེད་དུ་འཇུག་པའི་འགལ་རྟགས།
   e.g. product, because if it is impermanent, it is pervaded by being a product.
2. Contradictory sign that partially applies to the discordant class
   མི་མཐུན་ཕྱོགས་ལ་རྣམ་གཉིས་སུ་འཇུག་པའི་འགལ་རྟགས།
   e.g. instance of product, because if it is impermanent, it is not pervaded by being an instance of product, (e.g. product).

(See: Two types of sign pervasion)

Moreover, product is the contradictory sign in the proof that sound is permanent because it is the correct sign in the proof that sound is impermanent; because those two are mutually pervasive.

There does not exist a contradictory sign in the proof that sound is impermanent because if it is an incorrect sign in the proof that sound is impermanent, then it is necessarily either an Indefinite sign in the proof of that or a Non-established sign in the proof of that.

Up a level: Pseudo signs