A subset of a topological space is called clopen if it is both open and closed.
If a space has finitely many connected components then each connected component is clopen. This may not be the case if there are infinitely many components, as the case of the rational numbers demonstrates.
|Date of creation||2013-03-22 13:25:29|
|Last modified on||2013-03-22 13:25:29|
|Last modified by||mathcam (2727)|
|Synonym||closed and open|