{HEAD ~ at least a part} of the first element is closer to {TAIL ~ the front surface} than the second element is to the front surface 
is closer to
{ HEAD ~ at least a part } of the first element is closer to { TAIL ~ the front surface } than the second element is to the front surface
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH