evaluating {HEAD ~ a conversion capability} of {TAIL ~ the catalytic converter volume} on the basis of a value which is a function of the first difference, the value being normalized to a value which is a function of the second difference 
of
evaluating { HEAD ~ a conversion capability } of { TAIL ~ the catalytic converter volume } on the basis of a value which is a function of the first difference , the value being normalized to a value which is a function of the second difference
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH