#subgroup.mathematical_group  (mathematics) a subset (that is not empty) of a mathematical group
  supertype:  #mathematical_group__group  a set that is closed, associative, has an identity element and every element has an inverse
     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 #subgroup.mathematical_group; click here to add one.