Pāṇini sūtras

aṭ acutely accented is the augment of the verbal stem in the Aorist, Imperfect and the Conditional.

German Im Aorist, Imperfect und Conditionalis tritt betontes a vor die Wurzel. (71)

1. luṅ+laṅ+lṛṅkṣuलुङ्+लङ्+लृङ्क्षु

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   lल्	luṅलुङ्	luṅलुङ्	aorist	luṅलुङ्
   lल्	laṅलङ्	laṅलङ्	imperfect (past)	laṅलङ्
   lल्	lṛṅलृङ्	lṛṅkṣuलृङ्क्षु	conditional	lṛṅलृङ् + plus kṣuक्षु

2. aṭ+udāttaḥअट्+उदात्तः

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   aअ	aṭअट्	aṭअट्	aṭअट्	aṭअट्
   uउ	udāttaउदात्त	udāttaḥउदात्तः	udāttaउदात्त	udāttउदात्त् + plus aḥअः

Anuvṛtti

1. bhātभात् 6·4·22

   Part	Lexeme	Sandhi form	Meaning	Stem + termination
   bब्	bhaभ	bhātभात्	bhaभ	bhभ् + plus ātआत्