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