Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision | |||
|
topological_space [2015/02/26 20:24] nikolaj |
topological_space [2015/02/26 20:24] nikolaj |
||
|---|---|---|---|
| Line 12: | Line 12: | ||
| A comment on the intersection axiom requiring finiteness: A major motivation for topological spaces is $\mathbb R^n$ with the sets "open ball" and in this setting, an infinite intersection of open sets need not be open. E.g. consider the set of open intevals $(-\tfrac{1}{n},\tfrac{1}{n})$. | A comment on the intersection axiom requiring finiteness: A major motivation for topological spaces is $\mathbb R^n$ with the sets "open ball" and in this setting, an infinite intersection of open sets need not be open. E.g. consider the set of open intevals $(-\tfrac{1}{n},\tfrac{1}{n})$. | ||
| - | ==== Reference ==== | + | === Reference === |
| Wikipedia: [[http://en.wikipedia.org/wiki/Topological_space|Topological space]] | Wikipedia: [[http://en.wikipedia.org/wiki/Topological_space|Topological space]] | ||
