Circuit operation definition is performed in a front end environment with {HEAD ~ access} to integrated circuit computer aided design tools providing logic level and {TAIL ~ layout level information} concerning the integrated circuit 
to
Circuit operation definition is performed in a front end environment with { HEAD ~ access } to integrated circuit computer aided design tools providing logic level and { TAIL ~ layout level information } concerning the integrated circuit
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH