与所有模型一样，这是实际情况的简化视图：例如，没有“正在开发”这样的中间状态，因为这种状态的定义是主观的，意义不明确。
Like all models, this represents a simplified view of reality: there are no intermediate states under development for example, since the definitions of such states are subjective and ambiguous.
为了把不明确的概念减少到最少――并和多数现代的其它模型语言形成对比―― 第一个标准化的UML定义是用元模型来指定的。
To minimize ambiguity -- and in contrast to most other modeling languages of the time -- the first standardized definition of UML was specified using a metamodel.
自动化意味着模型(以及后来的模型语言)的不明确和不精密的消除，所以计算机程序能转换并熟练地操纵模型。
Automation implies the elimination of ambiguity and imprecision from models (and, hence, from the modeling language) so that computer programs can transform and manipulate models.
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