@zatR plus nounendings

pac पच् + /zatR
**paca- पचॱ + atR अतृ by several rules
→ pacatR by atoguNe अतोगुणे
→ !**pacat- पचत् "(who) is cooking" (remember that it is /Rdit)

**pacat- पचत् m +/su
→ pacant- पचन्त् + /su by ugidacAMs... because **pacat- पचत् is /Rdit
→ pacant पचन्त् by halGyAbbhyodIrgh...
→ pacan पचन् by saMyogAntasy...
→ !**pacan पचन् " s (he who) is cooking"

**pacat- पचत् m +/am
→ pacant- पचन्त् + am अम् by ugidacAMs... because **pacat- पचत् is /Rdit
→ !**pacantam पचन्तम् " o (he who) is cooking"

pac पच् + /zatR f
→ **pacantI- पचन्तीॱ f "(who) is cooking"

**pacantI- पचन्तीॱ +/su
→ pacantI पचन्ती by halGyAbbhyodIrgh...
→ !**pacantI पचन्ती " s (she who) is cooking"

**bhava- भवॱ + /zatR + /su
→ **bhavan भवन् "(he who) is becoming" — same steps as **pacan पचन् above