An equal number of additional write operations compensates for {HEAD ~ the additional reads} at {TAIL ~ a later point} 
An equal number of additional write operations compensates for { HEAD ~ the additional reads } at { TAIL ~ a later point }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL