由于DTD的复杂性，使得XFD的逻辑蕴涵问题研究比较困难。

Due to complicacy of DTD, it is difficult to study the logical implication of XFD.

youdao

编码后的DTD能在线性时间内对XML函数依赖的逻辑蕴涵问题进行判定。

Coding DTD can test the logical implication problem of XML function dependency in linear time.

youdao

实质蕴涵与逻辑蕴涵在经典命题逻辑中是一致的，但是二者并不是在任何逻辑中都一致。

Material and logical implication coincide in the classical logic, however they do not coincide in every logics.

youdao

So the mathematical notions of infinity or logical notions like logical entailment are beyond a child of this age.

因此,对于无限这个数学概念,或者是,像逻辑蕴涵这样的逻辑概念,超出了该年龄阶段儿童的理解范围

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