Pāṇini sūtras

Whatever is formed by the affix yat, has, if it is a disyllabic word, the acute on the first syllabic, with the exception of nāvya from nau

German Was das Suffix ya enthält, hat, wenn es zweisilbig ist, den Acut auf der ersten Silbe; ausgenommen ist nāvya. (213)

1. yataḥयतः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   yय्	yatयत्	yataḥयतः	yatयत्	yatयत् + plus aḥअः

2. a+nāvaḥअ+नावः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	aअ	aअ	not	aअ
   nन्	nauनौ	nāvaḥनावः	nau [word]	nauनौ + plus aḥअः

Anuvṛtti

1. udāttaḥउदात्तः 6·1·159

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

2. ādiḥआदिः 6·1·197

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