repeating the sequence of {HEAD ~ steps} through with {TAIL ~ respect} to subsequent substrate elements in the series 
through with
repeating the sequence of { HEAD ~ steps } through with { TAIL ~ respect } to subsequent substrate elements in the series
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH