实验内容：根据课堂讲授的形式化算法，编制程序实现一个预测分析器，能对常见的算术表达式语句进行分析

实验要求：

a)组织算术表达式的输入；

b)若输入的符号串是一个算术表达式语句，则输出分析过程，否则输出一个错误-Experiment: algorithm according to the formal classroom teaching, the preparation process to achieve a prediction analyzer, capable of common arithmetic expression analysis of experimental requirements statements: a) Organization of input arithmetic expression　b) if the input string is a symbol arithmetic expression statements, the output of the process, or output an error