A memory cell with a threshold voltage in {TAIL ~ a forbidden zone} can be flagged as {HEAD ~ a data error} or corrected by increasing or decreasing the threshold voltage to an adjacent allowed state 
A memory cell with a threshold voltage in { TAIL ~ a forbidden zone } can be flagged as { HEAD ~ a data error } or corrected by increasing or decreasing the threshold voltage to an adjacent allowed state
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH