Relation pm#binary_relation (?,?)  in WebKB, most relation types are binary and some have a variable number of arguments (as in KIF), hence this type is currently only specialized by types that I do not want to see as direct subtypes of pm#relation
  exclusion:  ternary_relation  quaternary_relation  relation_with_variable_arity
  supertype:  relation_with_particular_property  this rather fuzzy type permits to group categorization schemes less common than those covered by the previous sibling categories
  instance of:  binary_relation_type
  subtype:  unary_function__unaryfunction (? -> ?)  function that requires a single argument; currently not specialized by the SUMO ternary relations since this seems useless (for now)
  subtype:  Relation (?,?)  to specify a reference to a related resource; in WebKB, pm#relation or MORE PRECISE RELATION TYPES SHOULD BE USED INSTEAD
     subtype:  refers (?,?)  the 1st argument mentions or includes a reference to the 2nd argument, e.g., an article whose topic is a recent change in the price of oil may refer to many other things, e.g., the general state of the economy, the weather in California, the prospect of global warming, the options for alternative energy sources, the stock prices of various oil companies, etc.
        subtype:  names__name (string,?)  the string names the 2nd argument
           subtype:  unique_identifier (string,?)  the string uniquely identifies the 2nd argument
        subtype:  represents (?,?)  the 1st argument in some way indicates, expresses, connotes, pictures, describes ... the 2nd argument
           subtype:  contains_information (content_bearing_object,proposition)  relates a content_bearing_object to the proposition it expresses; examples include the relationships between a physical novel and its story and between a printed score and its musical content
           subtype:  realization (?,?)
        subtype:  see_also__seealso (?,entity)
           subtype:  is_defined_by (?,entity)  in WebKB, pm#definition SHOULD BE USED INSTEAD
              subtype:  definition (?,description_content/medium/container)  see also #definition
                 subtype:  definition (description_content/medium/container,description_content/medium/container)  a logical relation should be used instead of this relation
           subtype:  imports__import (?,entity)  if imports(X,Y) and you believe X, then you should believe what is in Y
  subtype:  Type (?,entity)  to specify the nature or genre of the content of a resource; SHOULD NOT BE USED IN WEBKB
     subtype:  instance (?,set_or_class)  if the common reading conventions of parameters had been respected, this type would have been named instance_of; an object is an instance of a set_or_class if it is included in that set_or_class; an individual may be an instance of many classes, some of which may be subclasses of others; thus, there is no assumption in the meaning of instance about specificity or uniqueness
        subtype:  kind__type___class___instance_of__instanceof (?,class)  the '^' link in the FT notation
        subtype:  immediate_instance__immediateinstance (?,set_or_class)  if the common reading conventions of parameters had been respected, this type would have been named immediate_instance_of; an object is an immediate_instance of a set_or_class if it is an instance of the set_or_class and there does not exist a subclass of set_or_class such that it is an instance of the subclass
  subtype:  Description (?,entity)  to specify an account of the content of a resource; in WebKB, pm#topic or pmdescr SHOULD BE USED INSTEAD
     subtype:  topic (?,entity)
        subtype:  annotation (?,description_content/medium/container)
           subtype:  descr (?,description_content/medium/container)  for connecting an object to a formal representation of it, e.g., a representation written with a fcg
           subtype:  Subject (description,entity)  to specify 1 or several topics; in WebKB, pm#descr SHOULD BE USED INSTEAD
           subtype:  origin (?,description_content/medium/container)
           subtype:  use (?,description_content/medium/container)
           subtype:  advantage (?,description_content/medium/container)
           subtype:  disadvantage (?,description_content/medium/container)
           subtype:  definition (?,description_content/medium/container)  see also #definition
           subtype:  role (?,description_content/medium/container)
           subtype:  requirement (?,description_content/medium/container)
           subtype:  issue (?,description_content/medium/container)
           subtype:  trap (?,description_content/medium/container)
     subtype:  url (?,URL)
     subtype:  file_or_file_element (?,description_container)
        subtype:  file (?,document_element)
           subtype:  home_page (?,document_element)
        subtype:  file_element (?,document_element)
        subtype:  descr_in__descrin (?,description_container)  when a thing t has a description stored in a description container dc, there is a relation pm#descr_in from t to dc
           subtype:  descr_container__description_support___descr_support (description,description_container)  permits to associate a statement with an object on which it is represented
     subtype:  version_info__versioninfo (? -> entity)  generally, a string giving information about this version; e.g., RCS/CVS keywords
     subtype:  title (? -> string)  for connecting an object to its "title" in a natural language
     subtype:  comment  for connecting an object to an informal representation of it, typically a node with a string inside; in WebKB, the FT and FCG notations permit to avoid using this relation type
  subtype:  relation_from_or_to_WordNet_type (*)
     subtype:  menu (meal_shop,food_or_beverage)
  subtype:  before (?,?)
     subtype:  before (time_measure,time_measure)
     subtype:  before_time (situation,time_measure)
     subtype:  later_situation__latersituation (situation,situation)
        subtype:  next_situation (situation -> situation)
           subtype:  successor (situation -> situation)
        subtype:  ending_situation__termination (situation -> situation)
        subtype:  postcondition (process,situation)
        subtype:  consequence (situation,situation)  see also rst#effect
  subtype:  after (?,?)
     subtype:  after (time_measure,time_measure)
     subtype:  until_time__untiltime__to_time (situation -> time_measure)
        subtype:  arrival_time__arrivaltime (process -> time_measure)
     subtype:  before_situation (situation,situation)  in WebKB, do not use these relations, use their inverses
        subtype:  previous_situation (situation -> situation)
        subtype:  beginning_situation__beginningsituation (situation -> situation)
        subtype:  precondition (process,situation)
        subtype:  cause (situation,situation)  see also rst#cause
           subtype:  causes (process,process)  the process in the 1st argument brings about the process in the 2nd argument