Set Analysis question

[tanjavarwijk]

Why gives these 2 rows not the same answer ?

Count(DISTINCT(if((Quantity<>0 and CYFlag=1 and [Shipping Agent Code]<>'KASSA'),Document_Nr)))

Count({$<CYFlag={1},[Shipping Agent Code]-={'KASSA'},Quantity-={0}>}DISTINCT(Document_Nr))

[MK_QSL]

Try

Count({$<CYFlag={1},[Shipping Agent Code]-={'KASSA'},Quantity={">0"}>}DISTINCT(Document_Nr))

[tanjavarwijk]

Quantity can also be negative