"block system" meaning in English

{
  "forms": [
    {
      "form": "block systems",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "block system (plural block systems)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Rail transportation",
          "orig": "en:Rail transportation",
          "parents": [
            "Transport",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 41",
          "text": "Signalling was by the standard 'block' system of the time, which prevents any two trains being on the same track section at once, but this was operated with boldness, with margins shaved. The Metropolitan would prove to have an excellent safety record nonetheless.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "On railways, a system by which the track is divided into sections of three or four miles, and trains are run by the guidance of electric signals so that no train enters a section or block before the preceding train has left it."
      ],
      "id": "en-block_system-en-noun-wgLYwMzD",
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "railway",
          "railway"
        ]
      ],
      "raw_glosses": [
        "(rail transport) On railways, a system by which the track is divided into sections of three or four miles, and trains are run by the guidance of electric signals so that no train enters a section or block before the preceding train has left it."
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    },
    {
      "categories": [
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Mathematics",
          "orig": "en:Mathematics",
          "parents": [
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "_dis": "33 67",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "Given a group G that acts on a set X, a partition of X that is G-invariant."
      ],
      "id": "en-block_system-en-noun-Few4R1PP",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "partition",
          "partition"
        ],
        [
          "invariant",
          "invariant"
        ]
      ],
      "raw_glosses": [
        "(mathematics) Given a group G that acts on a set X, a partition of X that is G-invariant."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ]
    }
  ],
  "wikipedia": [
    "en:Block (permutation group theory)"
  ],
  "word": "block system"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns"
  ],
  "forms": [
    {
      "form": "block systems",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "block system (plural block systems)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English terms with quotations",
        "en:Rail transportation"
      ],
      "examples": [
        {
          "ref": "2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 41",
          "text": "Signalling was by the standard 'block' system of the time, which prevents any two trains being on the same track section at once, but this was operated with boldness, with margins shaved. The Metropolitan would prove to have an excellent safety record nonetheless.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "On railways, a system by which the track is divided into sections of three or four miles, and trains are run by the guidance of electric signals so that no train enters a section or block before the preceding train has left it."
      ],
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "railway",
          "railway"
        ]
      ],
      "raw_glosses": [
        "(rail transport) On railways, a system by which the track is divided into sections of three or four miles, and trains are run by the guidance of electric signals so that no train enters a section or block before the preceding train has left it."
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    },
    {
      "categories": [
        "en:Mathematics"
      ],
      "glosses": [
        "Given a group G that acts on a set X, a partition of X that is G-invariant."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "partition",
          "partition"
        ],
        [
          "invariant",
          "invariant"
        ]
      ],
      "raw_glosses": [
        "(mathematics) Given a group G that acts on a set X, a partition of X that is G-invariant."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ]
    }
  ],
  "wikipedia": [
    "en:Block (permutation group theory)"
  ],
  "word": "block system"
}