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