{HEAD ~ The characteristic curves} of the diagram are defined with {TAIL ~ reference} to the minimum engine torque 
are defined with
{ HEAD ~ The characteristic curves } of the diagram are defined with { TAIL ~ reference } to the minimum engine torque
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH