采用三层文件实现彩灯的三种控制功能，使用于课堂实验练习-Three paper lanterns used to achieve the three control functions, the use of experimental practice in the classroom

pl0编译原理功能实现，它以赋值语句为基础，构造概念有顺序、条件和重复（循环）三种-pl0 compiler theory functions to achieve, it assignment based on the concept of sequential structure, conditions, and repeat (loop) three