Since {HEAD ~ the referencing} of {TAIL ~ the index nodes} 55 a c and storage nodes 56 a e is performed indirectly, for instance, by using Equations and , the structure of the message store 50 can be changed dynamically 
Since { HEAD ~ the referencing } of { TAIL ~ the index nodes } 55 a c and storage nodes 56 a e is performed indirectly , for instance , by using Equations and , the structure of the message store 50 can be changed dynamically
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH