#interval  a set containing all points (or all real numbers) between two given endpoints
  subtype: {#closed_interval #open_interval}  #sub-interval
  supertype:  #set  (mathematics) an abstract collection of numbers or symbols; "the set of prime numbers is infinite"
     supertype:  pm#collection  something gathering separated things (entities/situations)
        supertype:  pm#divisible_entity__divisibleentity  many classifications under this category are application-dependant
           supertype:  pm#entity  something that can be "involved" in a situation
              supertype:  pm#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:  pm#divisible_thing__divisiblething
              supertype:  pm#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 #interval; click here to add one.