"inversion pair" meaning in English

{
  "forms": [
    {
      "form": "inversion pairs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "inversion pair (plural inversion pairs)",
      "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": "topical",
          "langcode": "en",
          "name": "Mathematics",
          "orig": "en:Mathematics",
          "parents": [
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "a pair of integers (i,j) is an inversion pair of some permutation σ if iσ(j)."
      ],
      "id": "en-inversion_pair-en-noun-lifPlIQW",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "permutation",
          "permutation"
        ]
      ],
      "raw_glosses": [
        "(mathematics) a pair of integers (i,j) is an inversion pair of some permutation σ if iσ(j)."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ],
      "translations": [
        {
          "code": "fr",
          "lang": "French",
          "sense": "mathematics",
          "tags": [
            "feminine",
            "plural"
          ],
          "word": "paires en inversion"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "mathematics",
          "tags": [
            "masculine"
          ],
          "word": "Fehlstand"
        }
      ]
    }
  ],
  "word": "inversion pair"
}

{
  "forms": [
    {
      "form": "inversion pairs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "inversion pair (plural inversion pairs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Mathematics"
      ],
      "glosses": [
        "a pair of integers (i,j) is an inversion pair of some permutation σ if iσ(j)."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "permutation",
          "permutation"
        ]
      ],
      "raw_glosses": [
        "(mathematics) a pair of integers (i,j) is an inversion pair of some permutation σ if iσ(j)."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ]
    }
  ],
  "translations": [
    {
      "code": "fr",
      "lang": "French",
      "sense": "mathematics",
      "tags": [
        "feminine",
        "plural"
      ],
      "word": "paires en inversion"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "mathematics",
      "tags": [
        "masculine"
      ],
      "word": "Fehlstand"
    }
  ],
  "word": "inversion pair"
}