例如，这种理论模型允许用更有效的等价操作来代替关系代数操作同时不影响结果。

This theoretical model allows, for example, that relational algebra operations to be replaced by more efficient equivalent operations whereas not interfere with the result.

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该操作的一个等价实现方式如下所示。

An equivalent way of doing this would be the following.

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要模仿 JSF 默认错误处理和验证，还必须配置 Struts 使用验证器框架，或者在 ActionForm上的 validate方法中实现等价的操作。

To mimic JSF's default error handling and validation you would have to configure Struts to use the validator framework or implement the equivalent in the validate method on an ActionForm.

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