the survivability characteristics of {HEAD ~ the modified network} has deteriorated in comparison to {TAIL ~ the survivability characteristics} of the current network topology; and 
the survivability characteristics of { HEAD ~ the modified network } has deteriorated in comparison to { TAIL ~ the survivability characteristics } of the current network topology ; and
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH