Pāṇini sūtras

After the words upaka &c. there is optionally luk-elision of the Gotra affix when the words take the plural whether they enter into a Dvandva compound, or are used separately.

1. upaka+ādibhyaḥउपक+आदिभ्यः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   uउ	upakaउपक	upakaउपक	upaka [word]	upakउपक् + plus aअ
   āआ	ādiआदि	ādibhyaḥआदिभ्यः	etc.	ādआद् + plus ibhyãइभ्य̃

2. anyatarasyāmअन्यतरस्याम्

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	anyataraअन्यतर	anyatarasyāmअन्यतरस्याम्	optional	anyataraअन्यतर + plus syāmस्याम्

3. a+dvandveअ+द्वन्द्वे

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	aअ	aअ	not	aअ
   dद्	dvaṃdvaद्वंद्व	dvandveद्वन्द्वे	DvaṃdvaDवंद्व	dvaṃdvद्वंद्व् + plus eए

Anuvṛtti

1. lukलुक् 2·4·58

   Part	Lexeme	Sandhi form	Meaning	Stem
   lल्	lukलुक्	lukलुक्	suffix elision	lukलुक्

2. tena+evaतेन+एव 2·4·62

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   tत्	tadतद्	tenaतेन	that	tadतद् + plus aअ
   eए	evaएव	evaएव	indeed	evaएव

3. gotreगोत्रे 2·4·63

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   gग्	gotraगोत्र	gotreगोत्रे	Gotra	gotrगोत्र् + plus eए