By partitioning data into segments and by defining checkpoints based upon the segmentation, {HEAD ~ a process} may be restarted at {TAIL ~ each defined checkpoint} 
restarted at
By partitioning data into segments and by defining checkpoints based upon the segmentation , { HEAD ~ a process } may be restarted at { TAIL ~ each defined checkpoint }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL