wherein the A, B, C and D register values at the beginning of the time critical path are An, Bn, Cn, Dn, and further wherein {HEAD ~ the A, B}, C and D register {TAIL ~ values} at the end of the time critical path are An+4, Bn+4, Cn+4, Dn+4 
register
wherein the A , B , C and D register values at the beginning of the time critical path are An , Bn , Cn , Dn , and further wherein { HEAD ~ the A , B } , C and D register { TAIL ~ values } at the end of the time critical path are An+4 , Bn+4 , Cn+4 , Dn+4
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH