{HEAD ~ The horizontal advancing seat} is mounted on {TAIL ~ the slide block} of the vertical advancing seat and is provided with a slide block capable of sliding along the horizontal advancing seat in the horizontal direction relative to the base 
is mounted on
{ HEAD ~ The horizontal advancing seat } is mounted on { TAIL ~ the slide block } of the vertical advancing seat and is provided with a slide block capable of sliding along the horizontal advancing seat in the horizontal direction relative to the base
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH