The i of the verbal aṅga (stem) formed with the affix ṇi is elided before an ārdhadhātuka affix which does not take the augment iṭ ,
This debars इयङ्, the semi-vowel य, the guna, Vriddhi and the long substitutions. Thus अततक्षत्, अररक्षत्, आशिशत्, कारणा, हारणा, कारकः, हारकः, कार्यते, हार्यते and ज्ञीप्सति (see (VII. 4. I) for the shortening of the stem of the Aorists in these). Why do we say 'not having the augment इट्?' Observe कारयिता and हारयिता ॥,