Relation sumo#subclass__subclass_of (set_or_class,set_or_class)  if the common reading conventions of parameters had been respected, this type would have been named subclass_of; every instance of the 1st argument is also an instance of the 2nd argument; a class may have multiple superclasses and subclasses
  subtype:  immediate_subclass  the 1st argument is a subclass of the 2nd argument and there is no other subclass of the 2nd argument such that the 1st is also a subclass of the 2nd; in WebKB, use the link '<'
  type:  binary_predicate_type  the class of predicates relating two items - its valence is two
  type:  partial_ordering_relation_type  binary_relation that is reflexive, antisymmetric and transitive
  supertype:  subclass_of_or_equal (set_or_class,set_or_class)
     supertype:  relation_to_another_set_or_class (set_or_class,set_or_class+)  this category is needed to group SUMO relations between classes which cannot be subtype of pm#relation_from_type because their signatures curiously also involve sets
        supertype:  relation_between_collections (collection,collection+)
           supertype:  relation_from_collection (collection,*)
              supertype:  relation_from/to_thing_of_common_kind (*)  this type permits to categorize relations according to their signatures and hence offers (i) a concise way to set essential exclusion relations, and (ii) a systematic and easy-to-follow categorization
                 >part of:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
              supertype:  what_relation (*)
                 supertype:  wh-/how_relation (*)  this type permits to categorize relations according to the usual who/what/why/where/when/how questions ; this is a traditional but very subjective and ineffective way of categorizing relations 
                    >part of:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
           supertype:  relation_to_collection (*,collection)
              supertype:  relation_from/to_thing_of_common_kind (*)  this type permits to categorize relations according to their signatures and hence offers (i) a concise way to set essential exclusion relations, and (ii) a systematic and easy-to-follow categorization
              supertype:  what_relation (*)
        supertype:  relation_to_set_or_class (*,set_or_class)
           supertype:  relation_to_collection (*,collection)
  supertype:  partial_ordering_relation (?,?)  this category only serves structuration purposes: it is instance of pm#partial_ordering_relation_type which is not instance of pm#class_of_inheritable_relation_type
     supertype:  reflexive_relation__reflexiverelation (?,?)  this category only serves structuration purposes: it is instance of pm#reflexive_relation_type which is not instance of pm#class_of_inheritable_relation_type
        supertype:  binary_relation_with_particular_mathematical_property (?,?)
           supertype:  relation_with_particular_mathematical_property (*)
              supertype:  relation_with_particular_property (*)  this rather fuzzy type permits to group categorization schemes less common than those covered by the previous sibling categories
                 >part of:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
     supertype:  antisymmetric_relation__antisymmetricrelation (?,?)  this category only serves structuration purposes: it is instance of pm#antisymmetric_relation_type which is not instance of pm#class_of_inheritable_relation_type
        supertype:  binary_relation_with_particular_mathematical_property (?,?)
     supertype:  transitive_relation (?,?)  this category only serves structuration purposes: it is instance of pm#transitive_relation_type which is not instance of pm#class_of_inheritable_relation_type
        supertype:  binary_relation_with_particular_mathematical_property (?,?)