PGA3 Operator Question

Dave et al,

* This is a temporary solution until the cache is built.

I need to get a list of operators from the database that will return only
booleans types, not integer types. This is basically a list of possible
"join" operators.

This is the query I've found works the best. Do namespaces matter here? Can
anybody suggest a better query?

    SELECT DISTINCT
        a.oprname
    FROM
        pg_operator a
    JOIN
        pg_type b on ( a.oprresult = b.oid )
    WHERE
        a.oprkind = 'b' and b.typname = 'bool'
    ORDER BY
        a.oprname

-Keith