An enforcement mechanism uses {HEAD ~ the access rights} set up for {TAIL ~ the user} to determine whether to grant or deny accesses to resources 
set up for
An enforcement mechanism uses { HEAD ~ the access rights } set up for { TAIL ~ the user } to determine whether to grant or deny accesses to resources
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH