The

**union**of $E = \{ E_j \}_{j \in J}$ is the D11: Set \begin{equation} \bigcup_{j \in J} E_j : = \{ x \mid \exists \, j \in J : x \in E_j \} \end{equation}

▼ | Set of symbols |

▼ | Alphabet |

▼ | Deduction system |

▼ | Theory |

▼ | Zermelo-Fraenkel set theory |

▼ | Set |

▼ | Collection of sets |

Children

▶ | Disjoint union |

▶ | Set cover |

▶ | Successor set |

Results