{TAIL ~ A block placement generator} arranges sets of {HEAD ~ the interface objects} into block configurations within the interface 
{ TAIL ~ A block placement generator } arranges sets of { HEAD ~ the interface objects } into block configurations within the interface
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH