The equation gives the dynamic relation between the voltage U at and the power P through {HEAD ~ a connection} to {TAIL ~ the load} 
to
The equation gives the dynamic relation between the voltage U at and the power P through { HEAD ~ a connection } to { TAIL ~ the load }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL