# something related to Alexandrov one-point compactification

The topology^{} for $X\bigcup \{\mathrm{\infty}\}$ is defined as follows: there are two kinds of open sets of $X\bigcup \{\mathrm{\infty}\}$. If $\mathrm{\infty}\notin U$, then $U$ is open if and only if $U$ is an open set in the topology of $X$. If $\mathrm{\infty}\in U$, then $U$ is open if and only if $U$ is the complement of a closed compact subset $K$ of $X$.

Title | something related to Alexandrov one-point compactification |
---|---|

Canonical name | SomethingRelatedToAlexandrovOnepointCompactification |

Date of creation | 2013-03-22 17:03:54 |

Last modified on | 2013-03-22 17:03:54 |

Owner | adrianita (17056) |

Last modified by | adrianita (17056) |

Numerical id | 4 |

Author | adrianita (17056) |

Entry type | Definition |

Classification | msc 54D35 |