Apertures within each segmentation are ordered by minimizing {HEAD ~ the total leaf movement} between {TAIL ~ sets} of aperture shapes corresponding to adjacent delivery angles 
Apertures within each segmentation are ordered by minimizing { HEAD ~ the total leaf movement } between { TAIL ~ sets } of aperture shapes corresponding to adjacent delivery angles
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH