[Zope] Querying ZCatalog with indexes "in OR"

Hi everybody, I have a ZCatalog with a lot of indexes on boolean fields. If I query it from DTML, it returns correctly the results of a query like the SQL "SELECT xxxx WHERE (A=0 AND B=0 AND C=1)" I'd like to query it from DTML, obtaining the results as from the SQL query "SELECT xxxx WHERE (A=0 OR B=0 OR C=1)" How can I get that? Or where can I find infos about that? Mik