Karnatakabhashabhushana 1.1.2

1.1.2

atha śabdō ’yam ādau māṅgalyārthaḥ. māṅgalyādīni śāstrāṇi pradanta iti prasiddhēḥ. adhikārārthō vā. mayā karṇāṭa-viṣaya-śabda-siddhir adhikriyata ity arthaḥ.

Here the word "atha" is used at the beginning for the purpose of auspiciousness, according to the well-known dictum: "Treatises with auspicious beginnings flourish." Or it has the sense of a governing rule. The meaning is: the formation of words in the domain of Kannada is being undertaken by me.