In particular, {TAIL ~ if failure} of {HEAD ~ a CB server} 380 n is detected in stage 810, operation 800 proceeds to stage 820 
In particular , { TAIL ~ if failure } of { HEAD ~ a CB server } 380 n is detected in stage 810 , operation 800 proceeds to stage 820
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH