{TAIL ~ The blocks} of the invention comprise back {HEAD ~ legs} which are directed outwardly from the blocks back surface 
{ TAIL ~ The blocks } of the invention comprise back { HEAD ~ legs } which are directed outwardly from the blocks back surface
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH