deriv SD cv (242) ashtadhyayi.com hei.de L 242 ETT STT a 7.3.105 ALPH OLDHOMEPAGE NEWHOMEPAGE

AGi cApaH आङि चापः ONPANINI 73105

Before /TA (and /os), replace /Ap (with e ए).

**khaTvA- खट्वाॱ + /TA
→ khaTve- खट्वेॱ + /TA by this rule
→ khaTvay- खट्वय् + /TA by ecoyavAyAvaH
→ !**khaTvayA खट्वया "with a mat"

**azvA- अश्वाॱ + /TA
→ azve- अश्वेॱ + /TA
→ azvay- अश्वय् + /TA
→ !**azvayA अश्वया "with a mare"

**khaTvA- खट्वाॱ + /os → !**khaTvayos खट्वयोस् "of two mats"

**azvA- अश्वाॱ + /os → !**azvayos' अश्वयोस्ऽ "on two mares", sounds same as **azvayos अश्वयोस्

Before other endings, /Ap stays:

khaTvAbhyAm खट्वाभ्याम्

khaTvAbhiH खट्वाभिः

khaTvA- खट्वाॱ + /Gi
→ **khaTvAyAm खट्वायाम् "in bed"

But not always if the /Ap is after a pronoun — see **tasyAs तस्यास्, **sarvasyai सर्वस्यै.

Why is the /TA called /AG' in the sUtra?

I wish I knew.