{HEAD ~ Fault tolerant sync mark detector} for comparing {TAIL ~ a sign} and magnitude of a detected sequence to a target sync mark in sampled amplitude magnetic recording 
for comparing
{ HEAD ~ Fault tolerant sync mark detector } for comparing { TAIL ~ a sign } and magnitude of a detected sequence to a target sync mark in sampled amplitude magnetic recording
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH