#open_interval__unbounded_interval__unboundedinterval  an interval that does not include its endpoints
  exclusion:  closed_interval
  supertype:  interval  a set containing all points (or all real numbers) between two given endpoints
     supertype:  set  (mathematics) an abstract collection of numbers or symbols; "the set of prime numbers is infinite"
        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

No statement uses or specializes open_interval; click here to add one.