当然，这不能解决一个最终问题：最前面的非终结符表达式没有任何地方可以返回，所以您应该处理它生成的值。

Of course, this doesn't solve one last problem: the starting non-terminal expression has nowhere to return to, so you will need to do something with the values it produces.

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根据基因表达式编程的上下文无关文法模型，指出，基因表达式编程不能处理包含多个非终结符的上下文无关文法。

According 'to the context-free grammar model of GEP, the dissertation point out that Candida's GEP techniques cannot process context-free grammar with multiple none-terminals.

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