cocountable topology造句

例句与造句

1. The cocountable topology on a countable set is the discrete topology.
2. The cocountable topology on an uncountable set is countably metacompact, hence not compact.
3. But the cocountable topology is not discrete.
4. In fact, one could say that the cocountable topology on an uncountable set is " sequentially discrete ".
5. Every set " X " with the cocountable topology is T 1, as all singletons are closed.
6. It's difficult to find cocountable topology in a sentence. 用cocountable topology造句挺难的
7. An example of a space that is " not " sequential is the cocountable topology on an uncountable set.
8. Any set can be given the cocountable topology, in which a set is defined as open if it is either empty or its complement is countable.