Incearca: 

WHERE    (SELECT SUM(PRET_UNITAR) FROM dbo.DETAIL_FACTURI WHERE (ID_FACTURA = dbo.ANTET_FACTURI.ID))

-

COALESCE((SELECT SUM(PRET_UNITAR) FROM dbo.DETAIL_FACTURI WHERE (ID_FACTURA = dbo.ANTET_FACTURI.ID)) -
    (SELECT SUM(VALOARE) FROM dbo.CHITANTECL WHERE (ID_ANTET_FACTURA = dbo.ANTET_FACTURI.ID)),
    (SELECT SUM(PRET_UNITAR) FROM dbo.DETAIL_FACTURI WHERE (ID_FACTURA = dbo.ANTET_FACTURI.ID)))  > 0

Sau 

CREATE VIEW Fact

AS

SELECT dbo.PARTENERI.NUME,
    dbo.ANTET_FACTURI.ID AS aidi,
    dbo.ANTET_FACTURI.NUMECLIENT,
    dbo.ANTET_FACTURI.NRDOC,
    dbo.ANTET_FACTURI.DATA,
    dbo.ANTET_FACTURI.MONEDA,
    dbo.ANTET_FACTURI.SERIECARD,

    (SELECT SUM(PRET_UNITAR) FROM dbo.DETAIL_FACTURI WHERE (ID_FACTURA = dbo.ANTET_FACTURI.ID)) AS SUMA,

    COALESCE((SELECT SUM(PRET_UNITAR) FROM dbo.DETAIL_FACTURI WHERE (ID_FACTURA = dbo.ANTET_FACTURI.ID)) -
    (SELECT SUM(VALOARE) FROM dbo.CHITANTECL WHERE (ID_ANTET_FACTURA = dbo.ANTET_FACTURI.ID)),
    (SELECT SUM(PRET_UNITAR) FROM dbo.DETAIL_FACTURI WHERE (ID_FACTURA = dbo.ANTET_FACTURI.ID))) AS REST

FROM dbo.ANTET_FACTURI
    INNER JOIN dbo.PARTENERI ON dbo.ANTET_FACTURI.ID_PARTENER = dbo.PARTENERI.ID

si

SELECT *

FROM Fact

WHERE Suma - Rest > 0