CADLISP分式堆疊怎么寫源碼？

ap加載 輸入tjj統計線條個數。(defun c:tjj(/ ss )(setq ss (ssget '((0 . "LINE,LWPOLYLINE,CIRCLE,ARC,HELIX,ELLIPSE,SPLINE,POLYLINE"))))(alert(strcat"共選擇了：" (itoa (sslength ss))"條線段!"))(princ))(princ"\nCAD 命令窗口輸入“ap”加載本程序，輸入tjj運行程序!")