deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
The /Natvam rules won't change the n न् that is followed by a serious.
Why? No sUtra appears to say so! Then, how come **kurvanti कुर्वन्ति has n न् not N ण्?
/pANini doesn't bother to say a serious after the n न् debars /Natvam, because there is no need to say so. /Natvam does not affect kurvanti कुर्वन्ति because the /tripAdI rules work like an assembly line. See —
(A) When we form kurv कुर्व् + /anti''',
rule 83024 nazcApadAnt... COMPULSORILY changes kurvanti कुर्वन्ति into "kurvaMti"
BEFORE it gets to 84002 aTkupvAGnumvy....
(B) So aTkupvAGnumvy... won't trigger, because it affects only n न्, not M ं.
(C) Afterwards, rule 84058 anusvArasy...
changes back the M ं into n न्,
but that new n न् is /asiddha to the preceding rule aTkup अट्कुप्, so it stays.
As nazcApadAnt... does not work before funny, /Natvam works normally on a n न् that is followed by n न्, y य्... and so we get Nn ण्न् in **niSaNNa- निषण्णॱ.
Your explanation looks incomplete. If a n न् that is before another n न् in the same /pAda gets /Natvam, then why is there no kurvaNn कुर्वण्न् in kurvann api na lipyate कुर्वन्नपि न लिप्यते?
Because of asiddhambah... , first the inword rules form **kurvan कुर्वन्, afterwards the outword rule GamohrasvAd... doubles the n न्.