In Lesson 6, you learned the basic mechanics behind reactor-based applications. In Lesson 7, you will add functionality to this knowledge and create a garden path that knows how and when to modify itself. After testing your application and determining that it works satisfactorily, you will create a Visual LISP. application from your VLISP project.
You should consider this part of the tutorial as the advanced topics section. If you are a beginner, you may not understand all the AutoLISP. code presented here. There are several AutoLISP books listed at the end of this lesson that provide more thorough information on some of the advanced AutoLISP concepts presented here.