Pāṇini sūtras

Words denoting time, being in the accusative case, are optionally compounded with a word ending in a case-affix, when used in the sense of complete connection throughout with the time (i.e., duration of time) and the resulting compound is called Tat-purusha.

1. atyanta+saṃyogeअत्यन्त+संयोगे

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	atyantaअत्यन्त	atyantaअत्यन्त	complete	atyantअत्यन्त् + plus aअ
   sस्	saṃyogaसंयोग	saṃyogeसंयोगे	connection	saṃyogसंयोग् + plus eए

2. caच

   Part	Lexeme	Sandhi form	Meaning	Stem
   cच्	caच	caच	besides	caच

Anuvṛtti

1. dvitīyāद्वितीया 2·1·24

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   dद्	dvitīyaद्वितीय	dvitīyāद्वितीया	second	dvitīyद्वितीय् + plus āआ