{TAIL ~ The first rail element} 111 is disposed in {HEAD ~ the positive Z direction} right above the second rail element 112 
{ TAIL ~ The first rail element } 111 is disposed in { HEAD ~ the positive Z direction } right above the second rail element 112
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH