Relation sumo#smaller (object,*)
  type:  binary_predicate_type  the class of predicates relating two items - its valence is two
  type:  irreflexive_relation_type  r is irreflexive if r(?i,?i) holds for no value of ?i
  type:  transitive_relation_type  a binary_relation ?REL is transitive if (?REL ?INST1 ?INST2) and (?REL ?INST2 ?INST3) imply (?REL ?INST1 ?INST3), for all ?INST1, ?INST2, and ?INST3
  type:  spatial_relation_type  the class of relations that are spatial in a wide sense, e.g., mereological relations and topological relation
  supertype:  spatial_relation_from_entity_with_spatial_feature (object,*)
     supertype:  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:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
  supertype:  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:  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:  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 (?,?)