Pāṇini sūtras

The roots which are exhibited in Dhâtupâtha with a final vowel, may optionally have the acute on the first syllable, before the affixes of the Passive (yak), when the sense of the verb is Reflexive.

German Vocalisch auslautende Wurzeln können vor dem Suffix des Passivs -=ya den Acut auf der ersten Silbe haben, wenn das Verbum reflexive Bedeutung hat. (195)

1. a+caḥअ+चः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	aअ	aअ	akāraअकार	aअ
   cच्	cच्	caḥचः	CC	cच् + plus aḥअः

2. kartṛ+yakiकर्तृ+यकि

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   kक्	kartṛकर्तृ	kartṛकर्तृ	reflexivity	kartकर्त् + plus ṛऋ
   yय्	yakयक्	yakiयकि	yakयक्	yakयक् + plus iइ

Anuvṛtti

1. udāttaḥउदात्तः 6·1·159

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   uउ	udāttaउदात्त	udāttaḥउदात्तः	udāttaउदात्त	udāttउदात्त् + plus aḥअः

2. ādiḥआदिः 6·1·194

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   āआ	ādiआदि	ādiḥआदिः	first syllable	ādआद् + plus iḥइः