{HEAD ~ A storage space} is defined by {TAIL ~ a wall} which in its lower portion is provided with an inclined surface, which protrudes into the storage space 
is defined by
{ HEAD ~ A storage space } is defined by { TAIL ~ a wall } which in its lower portion is provided with an inclined surface , which protrudes into the storage space
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH