deriv SD cv (291) ashtadhyayi.com hei.de L 291 ETT STT a 7.1.55 ALPH OLDHOMEPAGE NEWHOMEPAGE

SaTcaturbhyaz ca

षट्चतुर्भ्यश्च ONPANINI 71055

Add /nuT to the /Am coming after a /SaT or /catur-.

So /Am turns into /nAm.

/catur- + /Am
→ /catur- + /nAm by this rule
→ !**caturNAm चतुर्णाम् "of four", with /Natvam

SaNNAm षण्णाम् with /Natvam of the nAm नाम् by napadAntATT...

The nounbases **paJcan- पञ्चन् **saptan- सप्तन् **aSTan- अष्टन् **navan- नवन् **dazan- दशन् lose their n न् by nalopaHprAt... before this consonant ending —

paJcan- पञ्चन् + /Am
→ paJcan- पञ्चन् + /nAm, by this rule
→ paJcAn- पञ्चान् + nAm नाम्, by nopadhAyAH
→ paJcA- पञ्चाॱ + nAm नाम्, by nalopaHprAt...
→ !**paJcAnAm पञ्चानाम्

The lengthening comes from nopadhAyAH — nAmi cannot lengthen the vowel because paJcan- पञ्चन् is a consonant base (and stays being a consonant base even after nalopaHprAt... removes the n न्).