problem with query logic for approvals

I want to find workitems where the verification approval was Approved by other than a specific set of people.
I cannot get the query to deal with the case of a workitem with 2 approvals on it -- I can include an AND condition inside the query which has Approval type is verification and Approval is not X, Y or Z and Approval descriptor cumulative status is Approved, but this does not distinguish the approvers between 2 approvals on the same workitem --it does not tie the approver to the type selected so if there is any approval on the workitem by someone else, it returns the workitem in the result set.
Any suggestions are appreciated
I cannot get the query to deal with the case of a workitem with 2 approvals on it -- I can include an AND condition inside the query which has Approval type is verification and Approval is not X, Y or Z and Approval descriptor cumulative status is Approved, but this does not distinguish the approvers between 2 approvals on the same workitem --it does not tie the approver to the type selected so if there is any approval on the workitem by someone else, it returns the workitem in the result set.
Any suggestions are appreciated
One answer

I want to find workitems where the verification approval was Approved by other than a specific set of people.
I cannot get the query to deal with the case of a workitem with 2 approvals on it -- I can include an AND condition inside the query which has Approval type is verification and Approval is not X, Y or Z and Approval descriptor cumulative status is Approved, but this does not distinguish the approvers between 2 approvals on the same workitem --it does not tie the approver to the type selected so if there is any approval on the workitem by someone else, it returns the workitem in the result set.
Any suggestions are appreciated
Brian,
I have similar issues with a condition such as
All Work items type=T in State=S AND (For all children (Child>type=CT implies Child>State=CS))
It seems if one child qualifies the query qualifies. I would be interested in getting more detail on how such things could be solved.
Ralph