用户绘制的DWG文件，实现线切割的路径的加工仿真，自动生成4G 加工代码
使用方法，在AUTOCAD下加载文件安装目录，并加载文件nc.lisp,加载成功后输入bb命令
选取刀具起点位置，根据提示选择加工路径，就会产生加工动态模拟，声称加工代码(The user draws the DWG file, realizes the processing simulation of the wire cutting path, and automatically generates the 4G processing code.
Using the method, load the file installation directory under AUTOCAD, and load the file nc.lisp. After loading is successful, enter the BB command.
Selecting the starting point of the tool and selecting the machining path according to the hints, the machining dynamic simulation will happen, and the processing code is claimed.)