Retrieving {HEAD ~ the target file} is made impractical by {TAIL ~ the deletion} of the reference to the target file in the directory manager file 
is made impractical by
Retrieving { HEAD ~ the target file } is made impractical by { TAIL ~ the deletion } of the reference to the target file in the directory manager file
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH