**finite matrix**if and only if $J$ is a D17: Finite set.

▼ | Set of symbols |

▼ | Alphabet |

▼ | Deduction system |

▼ | Theory |

▼ | Zermelo-Fraenkel set theory |

▼ | Set |

▼ | Binary cartesian set product |

▼ | Binary relation |

▼ | Map |

▼ | Countable map |

▼ | Array |

▼ | Matrix |