Proc means for data that meet two criteria

[ljljlj]

Hello, I need to use proc means only for rows that meet two criteria. For example:

pre   post    dif

1        0          -1

0       4           4

3       2           -1

0       0           0

5       5           0

I'd like to run proc means and exclude the 4th row.

I've tried using "where A ne 0 and B ne 0" and where "A ne 0 or B ne 0" and neither provide the correct output. Any help would be greatly appreciated!

Unsuccessful code:

proc means data=ABC mean sum;

var pre post dif;

where pre ne 0 and post ne 0;

run;

proc means data=ABC mean sum;

var pre post dif;

where pre ne 0 or post ne 0;

run;

[PaigeMiller]

I'd like to run proc means and exclude the 4th row.

	where not (pre eq 0 and post eq 0);

Alternatively

where (pre ne 0) or (post ne 0);

Your last code works for me.

[ballardw]

Provide example output for a given input set and describe why it is incorrect, especially for that second proc means code as @PaigeMiller indicates.