（1）根据给定文法，先求出FirstVt和LastVt集合，构造算符优先关系表（要求算符优先关系表输出到屏幕或者输出到文件）；

（2）根据算法和优先关系表分析给定表达式是否是该文法识别的正确的算术表达式（要求输出归约过程）

（3）实验要求独立完成，不允许有抄袭现象。

（4）实验完成后，要求提交源程序和上交实验报告（包括源程序清单）。

-(1) according to the given grammar, first find the FirstVt and LastVt collection of operator precedence relationship table structure (which requires operator precedence relationship table to the screen or output to a file)　(2) According to the algorithm and the priority of a given relational table identify whether the expression is the grammar correct arithmetic expression (requires output reduction process) (3) test requirements independently, does not allow copying phenomenon. (4) experiment is completed, and turned over requested source test report (including the source list).