#operator  (mathematics) a symbol that represents a function from functions to functions; "the integral operator"
  subtype:  #linear_operator  #identity_operator
  supertype:  #mathematical_function__function  a mathematical relation such that each element of one set is associated with at least one element of another set
     supertype:  #mathematical_relation  a relation between mathematical expressions (such as equality or inequality)
        supertype:  #relation  an abstraction belonging to or characteristic of two entities or parts together
           supertype:  pm#thing_that_can_be_seen_as_a_relation  usable as relation type
              supertype:  pm#thing_playing_some_role  category to classify things according to roles/viewpoints; classification under this category is application-dependant
                 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 #operator; click here to add one.