detect an inconsistency in data accepted into the system with {TAIL ~ a rule} from the third set of {HEAD ~ rules} 
detect an inconsistency in data accepted into the system with { TAIL ~ a rule } from the third set of { HEAD ~ rules }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD