Pāṇini sūtras

The s of stomaḥ is changed to ṣ after jyotis and āyus in a compound.

German In stoma nach jyotis und āyus. (83)

1. jyotiḥ+āyuṣaḥज्योतिः+आयुषः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   jज्	jyotisज्योतिस्	jyotiḥज्योतिः	jyotis [word]	jyotज्योत् + plus iḥइः
   āआ	āyusआयुस्	āyuṣaḥआयुषः	āyus [word]आयुस् [wओर्द्]	āyआय् + plus uṣa&उष&

2. stomaḥस्तोमः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   sस्	stomaस्तोम	stomaḥस्तोमः	stoma [word]	stomस्तोम् + plus aḥअः

Anuvṛtti

1. a+pada+antasyaअ+पद+अन्तस्य 8·3·55

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	aअ	aअ	not	aअ
   pप्	padaपद	padaपद	word	padपद् + plus aअ
   aअ	antaअन्त	antasyaअन्तस्य	last syllable	antअन्त् + plus asyaअस्य

2. i+ṇ+koḥइ+ण्+कोः 8·3·57

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   iइ	iइ	iइ	ikāraइकार	iइ
   ṇण्	ṇण्	ṇण्	NaNअ	ṇण्
   kक्	kuकु	koḥकोः	guttural	kक् + plus oḥओः

3. samāseसमासे 8·3·80

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   sस्	samāsaसमास	samāseसमासे	Sanskrit compound	samāsसमास् + plus eए

4. saḥसः 8·3·56

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   sस्	sस्	saḥसः	sakāraसकार	sस् + plus aḥअः