Relation 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
  subtype: {relation_from_situation spatial_relation_from_entity_with_spatial_feature relation_from_collection relation_from_description_content/medium/container relation_from_attribute_or_quality_or_measure} {relation_to_situation spatial_relation_to_entity_with_spatial_feature relation_to_time relation_to_collection relation_to_attribute_or_quality_or_measure}  prefLabel  related
  >part of:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type