说明：  CADlisp程序源代码，能实现多种CAD快捷命令。跟随CAD自动启动，并可以实现：双重偏移，自动标注圆、椭圆、多边形和封闭多义线的面积，统计线段长度，图层操作等等功能
(CADlisp program source code, it can achieve a variety of CAD shortcut commands. Following the CAD start automatically, and can realize the automatic tagging: a double offset, circle, ellipse, polygon and closed polyline area, statistical segment length, layer operation and so on)