 It harks back to the form of the inferential syllogism mentioned earlier in our discussion of the Ṣaṣṭi-tantra and the Vaiśeṣika-sūtra. However, there is one crucial difference: Vasubandhu is absolutely clear that the example statement expresses an indispensability relation (a-vinā-bhāva: lit. not existing without, or sine qua non). As is clear, instances of this schema are deductively valid arguments.