Dear @EH1

please recognize that ":A & :B" will always yield 1, if not at least one value of both is exactly zero. And comparison with ">= 0" consequently also yields 1.

So you would have to construct your formula another way: see proposal of Jim ":a>0 & :b>0" will work correctly, and sum is working like or, except that you might put an "if > 0" statement around to get only 0 or 1.

In formula editor below you can see the result of selected subexpression as well to better understand.

Georg