Eng 6012 inexists sp

Do you have IN tests with a join in the parent, specifically with different parent tables used in the IN's lhs and its subquery filters like "select * from r1, r2 where r1.col IN (select x from r3 where r3.col = r2.col)".
I want to make sure that the IN filter is getting handled as a 2-table filter in the parent query.