说明：  假设有以下文法： L-》En E-》E+T E-》E-T E-》T T-》T*F T-》T/F T-》F F-》(E) F-》id 设该文法进行自下而上计算时，打印出四则运算的计算结果。 E、T、F这些非终结符需要综合属性。以L属性的翻译方案为基础，将下表的语义规则嵌套在语法分析的过程中，即实现语法制导的翻译过程。
(Assume the following grammar: L->En E->E+T E->E-T E->T T->T*F T->T/F T->F F->(E) F->id Let the grammar print out the calculation results of four operations when calculating from bottom to top. E. The non terminal characters such as T and f need to integrate attributes. Based on the translation scheme of l-attribute, the semantic rules in the following table are nested in the process of grammar analysis, that is, the translation process of legal translation is realized.)