a second rail situated along {HEAD ~ the opposite side} of {TAIL ~ said work surface} from said first rail, wherein said first and second rails are oriented parallel to one another 
a second rail situated along { HEAD ~ the opposite side } of { TAIL ~ said work surface } from said first rail , wherein said first and second rails are oriented parallel to one another
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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