{TAIL ~ The propped block} 31 further has {HEAD ~ a slope} 311 formed between the propped surfaces 312, and 313 
{ TAIL ~ The propped block } 31 further has { HEAD ~ a slope } 311 formed between the propped surfaces 312 , and 313
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH