(defun exgrd ()
    (setq plii (nentsel))
    (setq plstrt (entnext(nth 0 plii))
          xplent (cdr(entget(nth 0 plii)))
          selent (cdr(assoc 0 xplent))
    )
    (if (eq selent "VERTEX")
      (setq plv (entget(entnext plstrt))
            plnxt (cdr(assoc -1 plv))
      )
    );setq
    (if (eq selent "VERTEX")
      (progn
        (while
           (/=(cdr(assoc 0(entget plnxt)))"SEQEND")
          (setq plv (entget(entnext plnxt))
                plnxt (cdr(assoc -1 plv))
          )
        )
        (setq nplhe (entget(cdr(assoc -2(entget plnxt))))
              plnxt (entnext(cdr(assoc -1 nplhe)))
        )
        (setq grd_pt_lst (list (cdr(assoc 10 nplhe))))
        (while
          (/=(cdr(assoc 0(entget plnxt)))"SEQEND")
          (setq plent (entget plnxt))
          (setq grd_pt_lst (append grd_pt_lst (list (cdr(assoc 10 plent)))))
          (setq plnxt (entnext(cdr(assoc -1(entget plnxt)))))
        )
      )
    )
)