I hope that someone would explain to me the way these codes are doing the trick .
Code:(defun Draw-Polyline (lst) (entmakex (list (cons 0 "POLYLINE") (cons 10 '(0 0 0)))) (mapcar (function (lambda (pt) (entmake (list (cons 0 "VERTEX") (cons 10 pt))))) lst ) (entmakex (list (cons 0 "SEQEND"))))