List x-values of Vertex of LWPOLYLINE

(defun KM:PTS (/ pl )
  (and
    (setq plst '())
    (setq pl (ssget '((0 . "LWPOLYLINE"))))
    (foreach 
      itm 
      (setq 
        ptlist 
        (mapcar 'cdr 
                   (vl-remove-if-not 
                     '(lambda (x) (= (car x) 10)) 
                     (entget (ssname pl 0))
                   )
        ); mapcar
      ); setq
      (setq plst (append plst (list itm)))
    ); foreach
  ); and
  (princ)
); defun pts

(defun KM:XPTS (/ plst)
  (setq xpts '())
  (KM:PTS)
  (foreach x plst (setq xpts (append xpts (list (car x)))))
  (setq xpts (LM:UNIQUE xpts))
  (vl-sort xpts '<)
)