FIGS 13A and 13B show {TAIL ~ a system} 450 according to the present invention which has {HEAD ~ a mouse hole} 451 associated with a rig 452  
FIGS 13A and 13B show { TAIL ~ a system } 450 according to the present invention which has { HEAD ~ a mouse hole } 451 associated with a rig 452
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH