LISP程序请教

选择部分图元
基点PT1
复制到PT2
并以PT2为基点旋转一个角度
看看以下的程序错在什么地方？？？
(defun C:ffc ()
(setq OM (getvar "OSMODE"))
(setvar "OSMODE" 33)
(setq SS nil)
(setq SS (ssget))
(setq PT1 (getpoint "\n 指定复制基点:"))
(setq PT2 (getpoint "\n 指定旋转基点:" PT1))
(setq ANG0 (getangle PT2 "\n 指定旋转角度:"))
(setq ANG (* (/ ANG0 PI) 180))
;
(setq n 0.0)
(setq slen (sslength SS))
(while (< n slen)
(setq ss1 (ssname ss n))
(command "copy" ss1 "" PT1 PT2)
(command "ROTATE" ss1 "" PT2 ANG)
)
(setvar "OSMODE" OM)
(PRINC)
)