输入已经消除左递归的以及提取公共左因子的LL(1)文法，再输入相应的表达式，若分析成功，则在递归输出过程中输出\"acc\",若不成功，则有相应的报错以及位置指名。注意，要把同一个非终结符的产生式分成单个输入。他会自动计算first,follow,预测分析表的构造，但并不输出。-importation has been eliminated and left recursive public from the left-LL (1) grammar, further importation of the corresponding expression, if the analysis is successful, the output of the recursive process output "belongs", if successful, there were errors and the corresponding location named. Attention, we should end with a non-escalation of production into a single input. He will be automatically calculated first, follow, and predicting and analyzing the table structure, but does not export.