赋值语句自上而下翻译系统的设计与实现. 设有如下文法： S → A A → V:=E E → E + T | T T → T * F | F F → (E) | digit V → i 采用递归下降分析法，并生成四元式-Design and Implementation of an assignment statement is a top-down translation system. Has the following grammar: S → AA