The affix kan coming after a Numeral ending with vat, takes optionally the augment id , the sense of the affix being those given up to [[5.1.63]],
The words ending in वत् are संख्या; see 1.1.23: and would consequently take कन् by 5.1.22. The present sutra ordains the optional affixing of इट् to this कन् ॥ Thus तावत्कः or तावतिकः, यावतिकः or यावत्कः ॥,