About index - "a query or data manipulation command can use at most one index per table"

Hello List,

A question about index. It mentioned in postgresql 8.0 doc "a query or 
data manipulation command can use *at most one index* *per table*". An 
example query is:

select * from A left join B using (id) where A.type='apple' and 
A.isExport=true;

"id" is the primary key for both table A & B. If index (type, isExport) 
has been created for table A. In the above query, will this index works?

Thanks a lot,
Emi