The next step comprises folding {HEAD ~ each} of {TAIL ~ the first slotted partitions} along its folding axis 
of
The next step comprises folding { HEAD ~ each } of { TAIL ~ the first slotted partitions } along its folding axis
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH