The ārhīya affix [[5.1.63]] is optionally elided after a dvigu occasioning compound, of the word niṣka preceded by dvi and tri,
The word द्विगोः 'a taddhita occasioning a Dvigu compound' of (V. I. 28) is to be read into this sutra. Thus द्विनिष्कम् or द्विनैष्किकम्, त्रिनिष्कम् or त्रिनैष्किकम् 7.3.17.
Vart:- So also when nishka is preceded by बहु e.g. बहुनिष्कम् or बहुनैष्किकम् ॥ The irregular Vriddhi of the second term is caused by 7.3.17.,