换句话说，对应xml语法中的每个概念定义相应的类：元素、属性、实体、文档。

In other words, classes are defined for every concept in the XML syntax: element, attribute, entity, documents.

youdao

这个概念也是非常合理的，因为事实上您不必为可能用到的每个文档都重新定义您的扩展。

This concept is also greatly justified by the fact that you don't actually have to re-define your extensions inline for every single document that may use them.

youdao

手写静态文档很难概念化过程，很难定义过程和它所相关联的内容。

Manual static documents can make it hard to conceptualize the process, and hard to see what the process is and all its related elements.

youdao