The spell checker employs {HEAD ~ a dictionary} wherein {TAIL ~ each word} of the dictionary has a signature associated with the word to facilitate searching for substitute words 
wherein
The spell checker employs { HEAD ~ a dictionary } wherein { TAIL ~ each word } of the dictionary has a signature associated with the word to facilitate searching for substitute words
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH