Relation pm#relation_playing_a_special_role (*)  this type permits to categorize relations according to their roles ; this is a traditional but quite subjective way of categorizing relations
  subtype: {pm#attributive_relation pm#mereological_relation pm#intentional_relation pm#temporal_relation pm#object_relation}  dl#conceptual_relation  pm#relation_for_an_application  pm#domain_related_relation
  >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type