极限序数

All superclasses of closed unbounded classes are stationary and stationary classes are unbounded, but there are stationary classes which are not closed and there are stationary classes which have no closed unbounded subclass ( such as the class of all limit ordinals with countable cofinality ).

所有闭合无界类的超类是固定的并且固定类是无界的，但是有着不闭合的固定类并且有着没有闭合无界子类的固定类(比如带有可数共尾性的所有极限序数的类)。

For example, the cofinality of ω is ω, because the sequence ω·''m''( where ''m'' ranges over the natural numbers ) tends to ω; but, more generally, any countable limit ordinal has cofinality ω.

例如，ω的共尾性是ω，因为序列ω·''m''(这里的''m''取值于自然数之上)趋向于ω；但是，更加一般的说，任何可数极限序数都有共尾性ω。

Notice that a number of authors define confinality or use it only for limit ordinals.

注意很多作者只对极限序数定义或使用共尾性。

Large ordinals can also be defined above the Church-Kleene ordinal, which are of interest in various parts of logic.

因此对于极限序数，存在着带有极限α的一个δ-标定的严格递增序列。

For example, the class of all limit ordinals is closed and unbounded : this translates the fact that there is always a limit ordinal greater than a given ordinal, and that a limit of limit ordinals is a limit ordinal (a fortunate fact if the terminology is to make any sense at all!).

例如，所有极限序数的类是闭合且无界的：这解释了总是有一个极限序数大于给定序数，而且极限序数的极限是极限序数的事实。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。