Relation pm#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
  subtype:  total_ordering_relation  inferior_or_equal_to  superior_or_equal_to  generalizing_type  subclass  specializing_type  constitution  part  wnMember  sub_collection  sub_attribute  sub_collection  less_than_or_equal_to  greater_than_or_equal_to  sub_list  initial_list  subsumes_content_class  subsumes_content_instance  temporal_part  before_or_equal  sub_process  sub_organization  geometric_part
  type:  partial_ordering_relation_type  binary_relation that is reflexive, antisymmetric and transitive
  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 (?,?)