a manipulator master arm having {HEAD ~ a manually operable control handle} at {TAIL ~ the free end} thereof, 
at
a manipulator master arm having { HEAD ~ a manually operable control handle } at { TAIL ~ the free end } thereof ,
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH