Pāṇini sūtras

In śṝ ‘to injure’ (IX.18) dṝ ‘to tear’ (IX.23) and pṝ ‘to protect’ (IX.19) the vowel may optionally be shortened in the Perfect.

1. śṝ+dṝ+prāmशॄ+दॄ+प्राम्

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   śश्	śṝशॄ	śṝशॄ	śṝशॄ	śṝशॄ
   dद्	dṝदॄ	dṝदॄ	dṛदृ	dṝदॄ
   pप्	pṝपॄ	prāmप्राम्	pṝपॄ	pṝपॄ + plus āmआम्

2. hrasvaḥह्रस्वः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   hह्	hrasvaह्रस्व	hrasvaḥह्रस्वः	short	hrasvह्रस्व् + plus aḥअः

3. vāवा

   Part	Lexeme	Sandhi form	Meaning	Stem
   vव्	vāवा	vāवा	optionally	vāवा

Anuvṛtti

1. liṭiलिटि 7·4·9

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   lल्	liṭलिट्	liṭiलिटि	perfect	liṭलिट् + plus iइ