Relation 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
  subtype:  asymmetric_relation  successor_attribute_closure  different  inverse  less_than  greater_than  increases_likelihood  decreases_likelihood  inhibits  prevents  sub_proposition  sub_plan  larger  smaller  starts  finishes  before  during  earlier  meets_spatially  overlaps_partially  superficial_part  connected_engineering_components  ancestor  sibling  brother  sister  spouse
  type:  irreflexive_relation_type  r is irreflexive if r(?i,?i) holds for no value of ?i
  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