The feminine affix cāp comes after a stem which is formed by the affix ñyaṅ or ṣyaṅ,
The affix यङ् here denotes and includes both the affixes ञ्यङ् (as taught in S. 171 of this chapter) and ष्यङ् (See 78) as it is the common element of both. Thus आम्बष्ठ्या 'woman of the race of Ambashthya', ससुवीर्या 'a woman of the race of Sauvirya', कौसल्या 'a woman of the race of Kausalya'.
Similarly ष्यङ् formed words, as, कारीषगन्ध्या, वाराह्या; बालाक्या ॥
Vart:- The affix चाप् comes in the feminine after a word ending with the affix यञ् when the letter ष् immediately precedes such yan. As शार्कराक्ष्य 'a female descendant of Sarkaraksha', पौतिमाष्या 'a female descendant of Putimashya', गौकाक्ष्या 'a female descendant of Gokasha'. These words belong to Gargadi class (IV. I. 105), and by sutra 16 would have taken ङीप् ॥
The प् of the affix चाप् is for the sake of forming a common term आप् with डाप् and टाप्; and the च regulates the accent making the final acute (VI. I. 163). The word गौकाक्ष्य is included in Kraudadi list 4.1.80 and takes the augment ष्यङ् in the feminine, and hence it would have taken चाप् by force of the present sutra and need not be included in the Vartika. There is no Samprasarana of the य when पुत्र or पति is added to this word 6.1.13, the form being गौकाक्ष्यापुत्रः and not गौकाक्षीपुत्रः ॥,