The terminal 5, said {HEAD ~ first and second encryption} means being constituted by {TAIL ~ a single encryption} means 
constituted by
The terminal 5 , said { HEAD ~ first and second encryption } means being constituted by { TAIL ~ a single encryption } means
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH