If you're calling PF, then you're not c-betting the flop.

I think you're confusing yourself trying to use terms like equity in a PF situation. Unless you make your hand on the flop, then it sounds like you're probably going to give up, so you need to improve to a winning hand 1/3 of the time on the flop.

I cant see a lot of value in this question though. It sounds like you're talking about an AI situation, but then you talk about postflop actions...