{
  "resource": "/api/exp/000/registries",
  "purpose": "Cardinality of the systems in which the identifier appears.",
  "registries": [
    {
      "system": "PubMed",
      "assignment": "sequential from 1",
      "approximate_size": 40000000
    },
    {
      "system": "Canadian patent applications",
      "assignment": "sequential",
      "approximate_size": 3400000
    },
    {
      "system": "European patent applications",
      "assignment": "sequential",
      "approximate_size": 4500000
    },
    {
      "system": "US patents",
      "assignment": "sequential",
      "approximate_size": 12000000
    }
  ],
  "consequence": "Every integer below the size of a sequentially assigned registry is an identifier in that registry. 2139847 is below all four. Its presence in each is therefore certain, not improbable.",
  "seven_digit_numbers": 9000000,
  "seven_digit_numbers_present_in_all_four": 2400000,
  "proportion": 0.267,
  "on_the_biological_theme": "Two of the largest sequentially assigned registries in existence index biomedical literature and patents. Any integer in range therefore lands on biological subject matter. The theme is a property of what humanity has catalogued, not of the number."
}