Pāṇini sūtras

The genitive affix is optionally elided after a stem ending in ṛ when svasṛ and pati follow, the relationship between the two words being through study or blood.

1. vibhāṣāविभाषा

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   vव्	vibhāṣविभाष्	vibhāṣāविभाषा	option	vibhāṣविभाष् + plus āआ

2. svasṛ+patyoḥस्वसृ+पत्योः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   sस्	svasṛस्वसृ	svasṛस्वसृ	svasṛ [word]स्वसृ [wओर्द्]	svasस्वस् + plus ṛऋ
   pप्	patiपति	patyoḥपत्योः	pati [word]	patपत् + plus yoḥयोः

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. ṣaṣṭhyāḥषष्ठ्याः 6·3·21

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   ṣष्	ṣaṣ̊षष्̊	ṣaṣṭhyāḥषष्ठ्याः	genitive	ṣaṣṭhषष्ठ् + plus yāया

3. vidyā+yoni+sambandhebhyaḥविद्या+योनि+सम्बन्धेभ्यः 6·3·23

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   vव्	vidyāविद्या	vidyāविद्या	eruditeness	vidyविद्य् + plus āआ
   yय्	yoniयोनि	yoniयोनि	family	yonयोन् + plus iइ
   sस्	sambandhaसम्बन्ध	sambandhebhyaḥसम्बन्धेभ्यः	kinship	sambandhसम्बन्ध् + plus ebhyãएभ्य̃