Vaisesika Sūtra 3.2.16

संदिग्धस्तूपचारः ॥१६॥

saṁdigdhaḥ tu upacāraḥ ॥16॥

[संदिग्धः (saṁdigdhaḥ) - doubtful; तु (tu) - but; उपचारः (upacāraḥ) - attribution;]

But the attribution is doubtful.