Function pm#complement_class (rdfs#class -> rdfs#class)  if something is not in one of the classes, then it is in the other, and vice versa; in WebKB, use the link '/'
  equal:  owl#complement_of (pm)
  supertype:  pm#exclusive_class__exclusiveclas (rdfs#class,rdfs#class)  the 2 classes have no common subtype/instance; in WebKB, use the link '!'
     supertype:  pm#relation_to_another_class (rdfs#class,rdfs#class+)
        supertype:  pm#relation_from_class_to_collection (rdfs#class,pm#collection)
           supertype:  pm#relation_from_type_to_collection (pm#type,pm#collection)
              supertype:  pm#relation_between_collections (pm#collection,pm#collection+)
                 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:  pm#relation_to_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
                    supertype:  pm#what_relation (*)
              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_class (rdfs#class,*)
              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_to_another_set_or_class (pm#set_or_class,pm#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:  pm#relation_between_collections (pm#collection,pm#collection+)
           supertype:  pm#relation_to_set_or_class (*,pm#set_or_class)
              supertype:  pm#relation_to_collection (*,pm#collection)
     supertype:  pm#disjoint (pm#set_or_class,pm#set_or_class)  like sumo#disjoint but from a a pm#set_or_class to another
        supertype:  pm#relation_to_another_set_or_class (pm#set_or_class,pm#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:  pm#exclusive_type__exclusivetype (pm#type,pm#type)  in WebKB, use the '!' link
        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#different__different_from__differentfrom (?,?)
        supertype:  pm#irreflexive_relation__irreflexiverelation (?,?)  this category only serves structuration purposes: it is instance of pm#irreflexive_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#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:  pm#binary_relation_with_particular_mathematical_property (?,?)
  supertype:  pm#complement_type (pm#type -> pm#type)  a supertype of owl#complement_of which can only connect RDFS/OWL classes
     supertype:  pm#closed_exclusion (pm#type -> pm#type)  the '/' link in the FT notation:  the two linked types either are respectively identical to pm#thing and pm#nothing (they are "complement types") or they subtype a same type and form a complete subtype partition
        supertype:  pm#exclusive_type__exclusivetype (pm#type,pm#type)  in WebKB, use the '!' link