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  "body": "\n## Summary\n\nA relational structure is a set together with a family of relations on it and no operations.\nIt is a [[structure|983GZBQYT4]] for a [[signature|WDVVEYD6AT]] that has only relation symbols.\nGraphs, partially ordered sets and sets with an equivalence relation are relational structures.\nThey are the other extreme from [[algebraic structures|QJGPT2W0FT]], which have only operations.\n\n## Explanations\n\n### L1 human\n\nA relational structure is a set where some tuples of elements are marked as related.\nA graph is the simplest example: the set is the set of vertices, and two vertices are related when there is an edge between them.\nA [[partial order|0QV2JS9RJ3]] such as $\\le$ on the integers is another example with one binary relation.\nNothing is computed in a relational structure; one only asks whether given elements are related.\n",
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