conditions of FOX to write data?

hi everyone.

can u tell what conditions are to write data in cube.

for example

FOREACH char2

(KF, char1, char2) = 3.

ENDFOR.

fox will put 3 only if there were 1at this data slice.

in what slices should i put data befire executing fox formula?

1.all char1 values and kf

2.all char2 values and kf

now my fox formula works only if i put data (1) in combination char1 and char2 with kf before executing formula.