{HEAD ~ The positions} of {TAIL ~ the tracers} is determined by differential transformers having cores fixed for radial movement with respective tracers 
of
{ HEAD ~ The positions } of { TAIL ~ the tracers } is determined by differential transformers having cores fixed for radial movement with respective tracers
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