{HEAD ~ The data} is supplied from the buffer 91 to {TAIL ~ the image comparator} 92 
is supplied to
{ HEAD ~ The data } is supplied from the buffer 91 to { TAIL ~ the image comparator } 92
HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH