More simply stated, calculating circuit 5 functions as a calculating means that calculates and produces {HEAD ~ inductor voltage V5} and adds inductor current J4 to secondary current J2 to calculate {TAIL ~ a corrected signal} 
More simply stated , calculating circuit 5 functions as a calculating means that calculates and produces { HEAD ~ inductor voltage V5 } and adds inductor current J4 to secondary current J2 to calculate { TAIL ~ a corrected signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL