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