Probability

Hi guys.

Here is a probability question.

Let:

f(d, w) = p(d, w);
f ’ (d, w) = p(d’,w’)p(d|d’)p(w|w’)=p(d’,w’) {p(d)/ p(d’)}{p(w)/ p(w’)};
f (d) = sum_w {f(d, w)};
f ‘ (d)= sum_w { f ‘ (d, w)};
f(d|w) = f(d, w) / f(w);
f ‘ (d | w) = f ‘ ( d, w) / f ‘ (w)


To Show: p(w’ | d’) p(w | w’) = f ‘ ( w | d’ );



Thanks!