projecting a patterned beam of radiation onto {HEAD ~ a substrate} held on {TAIL ~ the substrate table} 
held on
projecting a patterned beam of radiation onto { HEAD ~ a substrate } held on { TAIL ~ the substrate table }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL