deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
The compounds that have the rootnoun /ac''' ("directed at", "beeing in") ifc have some peculiarities
These compounds can take the three genders.
When f , they are whimpy and get /GI.
When mn , some of them, like /pratyac- end up having three different forms, plus a special one with combining with /su —
/pratyac- + /su → **pratyaG प्रत्यङ्
/pratyac- → pratyaJc- प्रत्यञ्च् before other strong, as in **pratyaJcam प्रत्यञ्चम्
/pratyac- → pratyac- प्रत्यच् when /pada (which becomes pratyak प्रत्यक् by coHkuH, as in **pratyagbhis प्रत्यग्भिस्)
/pratyac- → pratIc- प्रतीच् when whimpy, as in **pratIcAm प्रतीचाम्
And others, like **prAc- प्राच्, have only two forms plus the special before /su —
**prAc- प्राच् + /su → **prAG प्राङ्
**prAc- प्राच् → prAJc- प्राञ्च् before other strong, as in **prAJcam प्राञ्चम्
**prAc- प्राच् → prAc- प्राच् when /pada (which becomes prAk प्राक् by coHkuH, as in **prAgbhis प्राग्भिस्)
**prAc- प्राच् → prAc- प्राच् when whimpy, as in **prAcAm प्राचाम्
There are a handful of compound bases formed with the rootnoun /ac''' "directed at", such as —
**dadhi- दधिॱ + /ac''' → **dadhyac- दध्यच्
/prati + /ac''' → **pratyac- प्रत्यच्
/pra + /ac''' → **prAc- प्राच्
/ut + /ac''' → **udac- उदच्
See also whitney on aJc.