Kavyadarsha 2.198

2.198

sajātīvyatireko 'yaṃ tamojāter idaṃ tamaḥ &
dṛṣṭirodhitayā tulyaṃ bhinnam anyair adarśi tat //iti vyatirekacakram//

This is contrast within the same class [sajātīyavyatireka]: this darkness of the genus darkness,
similar in obstructing sight, is shown to be different by other qualities.
Thus ends the cycle of contrast (vyatireka).