The assembly comprises a plurality of first slotted partitions intersecting with a plurality of {HEAD ~ second slotted partitions} to form {TAIL ~ a collapsible matrix} 
The assembly comprises a plurality of first slotted partitions intersecting with a plurality of { HEAD ~ second slotted partitions } to form { TAIL ~ a collapsible matrix }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL