# internal node (of a tree)

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An *internal node ^{}* of a tree is any node which has degree greater than one. Or, phrased in rooted tree

^{}terminology, the internal nodes of a tree are the nodes which have at least one child node.

$$\text{xymatrix}{}{\mathrm{\&}}{\bullet}\text{ar}\mathrm{@}-[dl]\text{ar}\mathrm{@}-{[}{d}{}{r}{]}{}{\mathrm{\&}}{}{\mathrm{\&}}{}{\mathrm{\&}}{\bullet}{\mathrm{\&}}{}{\mathrm{\&}}{\bullet}\text{ar}\mathrm{@}-[dr]\text{ar}\mathrm{@}-{[}{d}{}{l}{]}{}{\mathrm{\&}}{}{\mathrm{\&}}{}{\mathrm{\&}}{\bullet}\text{ar}\mathrm{@}-[dl]\mathrm{\&}\mathrm{\&}\bullet \mathrm{\&}\bullet \mathrm{\&}\mathrm{\&}\mathrm{\&}\mathrm{\&}$$ |

Figure: A tree with internal nodes highlighted in red.

Title | internal node (of a tree) |
---|---|

Canonical name | InternalNodeofATree |

Date of creation | 2013-03-22 12:30:25 |

Last modified on | 2013-03-22 12:30:25 |

Owner | akrowne (2) |

Last modified by | akrowne (2) |

Numerical id | 6 |

Author | akrowne (2) |

Entry type | Definition |

Classification | msc 05C05 |

Synonym | internal node |