{HEAD ~ A second semiconductor well} of {TAIL ~ the first conductivity type} is disposed in the first semiconductor well 
{ HEAD ~ A second semiconductor well } of { TAIL ~ the first conductivity type } is disposed in the first semiconductor well
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH