#blood_group__bloodgroup__blood_type__bloodtype  people whose blood (usually just the red blood cells) has the same antigens
  subtype:  group_A  group_B  group_AB  group_O  Rh-positive_blood_type  Rh-negative_blood_type
  supertype:  people  (plural) any group of human beings (men or women or children) collectively; "old people"; "there were at least 200 people in the audience"
     supertype:  group__grouping  any number of entities (members) considered as a unit
        supertype:  collection  something gathering separated things (entities/situations)
           supertype:  divisible_entity__divisibleentity  many classifications under this category are application-dependant
              supertype:  entity  something that can be "involved" in a situation
                 supertype:  thing__something___T__t___3D_or_4D_thing_or_anything_else  any category (type or individual) is instance of this type; any type is also a subtype of this type
              supertype:  divisible_thing__divisiblething
                 supertype:  thing__something___T__t___3D_or_4D_thing_or_anything_else  any category (type or individual) is instance of this type; any type is also a subtype of this type

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