求翻译：定义UML符号的表示法，为开发者或开发工具使用这些图形符号和文本语法为系统建模提供了标准。这些图形符号和文字所表达的是应用级的模型，在语义上它是UML元模型的实例。　是什么意思？

Defined uml notation symbols, use graphical symbols and text syntax for the developer or development tools provide a standard for system modeling. Graphical symbols and text to express the application-level model, it is semantically uml metamodel instance.

Definition of the symbol UML notation, as a developer or development tools use these graphical symbols and text syntax for system modeling provides a standard. These graphical symbols and text is expressed by the application-level model, the semantic UML meta model it is the instances.

Defines the UML mark the method of portrayal, used these graph mark and the text grammar for the exploiter or the development kit has provided the standard for the system modelling.What these graph mark and the writing express is applies the level the model, in the semantics it is the UML Yuan model

Define a notation for UML symbols, to developers or development tools to use these graphic symbols and text syntax provides a standard for modeling.　These graphic symbols and text expression by application-level model, semantically it is the UML metamodel instance.

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