guṇa is substituted for the vowel of the root before the affix aṅ in the roots ending in ṛ or ṝ as well as dṛś 'to see'.,
As शकलाङ्गुष्ठकोऽकरत्, अहं तेभ्योऽकरं नमः, असरत्, आरत्, अदर्शत्, अदर्शताम्, अदर्शन् ॥ The affix अङ् means the Aorist-character अङ् of which the above examples are given. It also is the krit-affix 3.3.104. of which we have जॄ--जरा ॥
The word अकरत् is अङ् Aorist formed from कृ by (III. I. 59). The word असरत् is from सृ (III. I. 56). अदर्शत् by (VI. I. 57).,