Preferably, {HEAD ~ the current transaction information} is used to update both the remote ledger and {TAIL ~ the shadow ledger} 
is used to update
Preferably , { HEAD ~ the current transaction information } is used to update both the remote ledger and { TAIL ~ the shadow ledger }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL