Pāṇini sūtras

The affix ṭach comes after the word śvan ending in a Tatpurusha compound, when another thing not being a living object is compared with it.

1. upamānātउपमानात्

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   uउ	upamānaउपमान	upamānātउपमानात्	comparison	upamānउपमान् + plus ātआत्

2. a+prāṇiṣuअ+प्राणिषु

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	aअ	aअ	not	aअ
   pप्	prāṇinप्राणिन्	prāṇiṣuप्राणिषु	animated	prāṇप्राण् + plus iṣuइषु

Anuvṛtti

1. samāsa+antāḥसमास+अन्ताः 5·4·68

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   sस्	samāsaसमास	samāsaसमास	Sanskrit compound	samāsसमास् + plus aअ
   aअ	antaअन्त	antāḥअन्ताः	end	antअन्त् + plus āMआM

2. tatpuruṣasyaतत्पुरुषस्य 5·4·86

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   tत्	tatpuruṣaतत्पुरुष	tatpuruṣasyaतत्पुरुषस्य	tatpuruṣaतत्पुरुष	tatpuruṣतत्पुरुष् + plus asyaअस्य

3. ṭacटच् 5·4·91

   Part	Lexeme	Sandhi form	Meaning	Stem
   ṭट्	ṭacटच्	ṭacटच्	ṭacटच्	ṭacटच्

4. śunaḥशुनः 5·4·96

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   śश्	śvanश्वन्	śunaḥशुनः	śvan [word]श्वन् [wओर्द्]	śvश्व् + plus naḥनः