{HEAD ~ The runner} 44 is accommodated at {TAIL ~ the fixing portion} 431, and is capable of up and down sliding movements at the fixing portion 431 
{ HEAD ~ The runner } 44 is accommodated at { TAIL ~ the fixing portion } 431 , and is capable of up and down sliding movements at the fixing portion 431
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH