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