Relation owl#equivalent_property (pm#binary_relation_type,pm#binary_relation_type)  in WebKB, use the link '='
  exclusion:  owl#equivalent_class
  equal:  daml#same_property_as (owl)
  supertype:  pm#same_type_as (pm#type,pm#type)
     supertype:  pm#relation_from_type (pm#type,*)  type of relations from a concept/relation type, i.e. in RDFS terminology, from a class or a property
        supertype:  pm#relation_from_collection (pm#collection,*)
           supertype:  pm#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:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
           supertype:  pm#what_relation (*)
              supertype:  pm#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:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
     supertype:  owl#same_as (?,?)  MORE PRECISE TYPES THAN THIS ONE SHOULD BE USED
        supertype:  pm#equal (?,?)  "=" in KIF; true if the 1st argument is identical to the 2nd
           supertype:  pm#equivalence_relation__equivalencerelation (?,?)  this category only serves structuration purposes: it is instance of pm#equivalence_relation_type which is not instance of pm#class_of_inheritable_relation_type
              supertype:  pm#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:  pm#binary_relation_with_particular_mathematical_property (?,?)
                    supertype:  pm#relation_with_particular_mathematical_property (*)
                       supertype:  pm#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:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
              supertype:  pm#symmetric_relation__symmetricrelation (?,?)  this category only serves structuration purposes: it is instance of pm#symmetric_relation_type which is not instance of pm#class_of_inheritable_relation_type
                 supertype:  pm#binary_relation_with_particular_mathematical_property (?,?)
              supertype:  pm#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:  pm#binary_relation_with_particular_mathematical_property (?,?)
  supertype:  pm#relation_to_another_binary_relation_type (pm#binary_relation_type,pm#binary_relation_type)
     supertype:  pm#relation_from_binary_relation_type (pm#binary_relation_type,*)
        supertype:  pm#relation_from_relation_type (pm#relation_type,*)
           supertype:  pm#relation_from_type (pm#type,*)  type of relations from a concept/relation type, i.e. in RDFS terminology, from a class or a property