A folder that is {HEAD ~ a member} of {TAIL ~ a federated folder} can also be a federated folder 
of
A folder that is { HEAD ~ a member } of { TAIL ~ a federated folder } can also be a federated folder
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH