यचि भम्

And when an affix with an initial य् or an initial vowel, being one of the affixes, beginning with सु and ending in क् , follows, not being सर्वनामस्थान , then what precedes, is called भ।
This debars the application of pada. Thus गर्ग + यञ् 4.1.105 = गार्ग्यः a grandson of Garga. So also वात्स्यः. The affix yan begins with a ya and the word garga being treated as Bha its final अ is elided before the affix by 6.4.148.

So also दक्ष + इञ् = दाक्षिः 4.1.95 grandson of Daksha प्लाक्षिः. Here the affix इञ् begins with a vowel the word standing before it being Bha, it causes elision of the final अ of daksha.

The word यचि is in the 7th case meaning when य् or अच् follow; and by the last Vart of Sutra 1.1.72, it means 'when an affix beginning with ya or ach follow.'

Vart:- The words नभस्, अङ्गिरस् and मनुष् should be treated as Bha when the affix वत् follows. Thus नभस्वत् like the sky. अङ्गिरस् like the Angiras. मनुष्वत् like the man. By being Bha, the स् is not changed into र्, which it would have been, had it been a pada 8.2.66.

Vart:- The words वृषन् is treated as Bha in the vedas when the words वसु and अश्व follow. Thus वृषण्वसुः; वृषणश्वस्य मेने Here had the word vrishan been treated as pada, the न would not have been changed into ण (See Rule 8.4.37); and this न would have been dropped before the affix vasu by 8.2.7.