deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
They are built with the rootnoun /aJcu aka /ac''', which means "that is at", "that is directed towards".
This rootnoun /aJcu is used only ifc. It is an /udit.
It has /kvin because of RtvigdadhRksr..., which makes it /kit too.
It loses the nasal because of aniditAMh..., becoming /ac'''.
Being /udit, it gets a nasal again when it is strong, by ugidacAMs....
Before strong, it gets /num by ugidacAMs... —
ac- अच् m + /am
→ aJc- अञ्च् + /am by ugidacAMs...
→ !**aJcam अञ्चम्
ac- अच् m + /au
→ !**aJcau अञ्चौ
ac- अच् m + /jas
→ !**aJcas अञ्चस्
ac- अच् n + /zi
→ !**aJci अञ्चि
But before strong /su (be it /sambuddhi or not) a funny thing happens —
ac- अच् + /su
When /ac is padafinal it becomes ak अक् normally by coHkuH —
ac- अच् n + /su OR /am → ak अक्
ac- अच् + /bhis → !**agbhiH अग्भिः
ac- अच् + /sup' → !**akSu अक्षु
Elsewhere (TITS, when it is whimpy) it stays —
ac- अच् + /TA
→ !**acA अचा as in **prAcA प्राचा
However, after a vowel, the a अ of a whimpy ac अच् is lost by acaH, and the vowel before it lengthens by cau —
/prati + /ac''' + /TA
→ /prati + **acA अचा
→ **pratIcA प्रतीचा
dadhi- दधिॱ + /ac''' + /TA
→ dadhi- दधिॱ + **acA अचा
→ **dadhIcA दधीचा
**viSvak- विष्वक् + /ac''' + /su → **viSvadryaG विष्वद्र्यङ्
viSvak विष्वक् + /ac''' + /TA → **viSvadrIcA विष्वद्रीचा