"signum function" meaning in English

{
  "forms": [
    {
      "form": "signum functions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "signum function (plural signum functions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
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          "source": "w"
        },
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          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
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          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Functions",
          "orig": "en:Functions",
          "parents": [
            "Algebra",
            "Calculus",
            "Geometry",
            "Mathematical analysis",
            "Mathematics",
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Mathematics",
          "orig": "en:Mathematics",
          "parents": [
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The function that determines the sign of a real number, yielding -1 if negative, +1 if positive, or otherwise zero."
      ],
      "hypernyms": [
        {
          "word": "function"
        }
      ],
      "id": "en-signum_function-en-noun-b4ZQ-6sh",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "sign",
          "sign"
        ],
        [
          "real number",
          "real number"
        ],
        [
          "negative",
          "negative"
        ],
        [
          "positive",
          "positive"
        ]
      ],
      "raw_glosses": [
        "(mathematics) The function that determines the sign of a real number, yielding -1 if negative, +1 if positive, or otherwise zero."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ],
      "translations": [
        {
          "code": "de",
          "lang": "German",
          "sense": "function",
          "tags": [
            "feminine"
          ],
          "word": "Signumfunktion"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "function",
          "word": "előjelfüggvény"
        },
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "znákovaja fúnkcija",
          "sense": "function",
          "tags": [
            "feminine"
          ],
          "word": "зна́ковая фу́нкция"
        },
        {
          "code": "tr",
          "lang": "Turkish",
          "sense": "function",
          "word": "işaret fonksiyonu"
        }
      ]
    }
  ],
  "word": "signum function"
}

{
  "forms": [
    {
      "form": "signum functions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "signum function (plural signum functions)",
      "name": "en-noun"
    }
  ],
  "hypernyms": [
    {
      "word": "function"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with non-redundant non-automated sortkeys",
        "en:Functions",
        "en:Mathematics"
      ],
      "glosses": [
        "The function that determines the sign of a real number, yielding -1 if negative, +1 if positive, or otherwise zero."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "sign",
          "sign"
        ],
        [
          "real number",
          "real number"
        ],
        [
          "negative",
          "negative"
        ],
        [
          "positive",
          "positive"
        ]
      ],
      "raw_glosses": [
        "(mathematics) The function that determines the sign of a real number, yielding -1 if negative, +1 if positive, or otherwise zero."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ]
    }
  ],
  "translations": [
    {
      "code": "de",
      "lang": "German",
      "sense": "function",
      "tags": [
        "feminine"
      ],
      "word": "Signumfunktion"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "function",
      "word": "előjelfüggvény"
    },
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "znákovaja fúnkcija",
      "sense": "function",
      "tags": [
        "feminine"
      ],
      "word": "зна́ковая фу́нкция"
    },
    {
      "code": "tr",
      "lang": "Turkish",
      "sense": "function",
      "word": "işaret fonksiyonu"
    }
  ],
  "word": "signum function"
}