Pāṇini sūtras

The final of viśva is lengthened before mitra when it is the name of a Rishi.

1. mitreमित्रे

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   mम्	mitraमित्र	mitreमित्रे	mitra [word]	mitrमित्र् + plus eए

2. ca+ṛṣauच+ऋषौ

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   cच्	caच	caच	besides	caच
   ṛऋ	ṛṣiऋषि	ṛṣauऋषौ	ṚṣiṚषि	ṛṣऋष् + plus auऔ

Anuvṛtti

1. uttara+padeउत्तर+पदे 6·3·1

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   uउ	uttaraउत्तर	uttaraउत्तर	last	uttarउत्तर् + plus aअ
   pप्	padaपद	padeपदे	word	padपद् + plus eए

2. pūrvasyaपूर्वस्य 6·3·111

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   pप्	pūrvaपूर्व	pūrvasyaपूर्वस्य	antecedent	pūrvaपूर्व + plus syaस्य

3. saṃhitāyāmसंहितायाम् 6·3·114

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   sस्	saṃhitāसंहिता	saṃhitāyāmसंहितायाम्	continuous speech	saṃhitसंहित् + plus āyआय्

4. viśvasyaविश्वस्य 6·3·128

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   vव्	viśvaविश्व	viśvasyaविश्वस्य	viśva [word]विश्व [wओर्द्]	viśvaविश्व + plus syaस्य