balibhugdhūmahetūtthadoṣādipratyayair yathā sthāṇutejo 'pramāṇādi parebhyo vyavasīyate
Just as [1] a post, [2] fire, and [3] invalidity are ascertained from external [sources] through the cognitions of [1] a crow, [2] smoke, and [3] defects arising from causes