yathā saṅghātatvasya / yato na saṅghātatvasya sādhyaviparyaye vyatirekitvaṃ saṃdigdham, asya tu saṃdigdham //
Just as in [the case of] being an aggregate, because the negative concomitance of being an aggregate with the opposite of what is to be proved is not doubtful, but this [your reason] is doubtful.