如何消除EBNF Instaparse语法中的歧义

Question

如何防止结构规则中的“，”文字在Instaparse的以下EBNF语法中被解析为运算符？

语法：

structure = atom <"("> term ("," term)* <")"> 
term = atom | number | structure | variable | "(" term ")" | term operator term
operator = "," | ";" | "\\=" | "=="

Answer 1

使用逗号作为分隔符和像你一样的运算符使得逗号上下文敏感，而Ebnf本身无法处理。