"congruence class" meaning in English

{
  "forms": [
    {
      "form": "congruence classes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "congruence class (plural congruence classes)",
      "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": [
        "An equivalence class of an equivalence relation that is a congruence."
      ],
      "id": "en-congruence_class-en-noun-rbOKOr4j",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "equivalence class",
          "equivalence class"
        ],
        [
          "equivalence relation",
          "equivalence relation"
        ],
        [
          "congruence",
          "congruence"
        ]
      ],
      "raw_glosses": [
        "(mathematics) An equivalence class of an equivalence relation that is a congruence."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ]
    }
  ],
  "word": "congruence class"
}

{
  "forms": [
    {
      "form": "congruence classes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "congruence class (plural congruence classes)",
      "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": [
        "An equivalence class of an equivalence relation that is a congruence."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "equivalence class",
          "equivalence class"
        ],
        [
          "equivalence relation",
          "equivalence relation"
        ],
        [
          "congruence",
          "congruence"
        ]
      ],
      "raw_glosses": [
        "(mathematics) An equivalence class of an equivalence relation that is a congruence."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ]
    }
  ],
  "word": "congruence class"
}