Function sumo#abstraction_fn__abstractionfn (sumo#class -> sumo#Attribute)  a unary_function that maps a class into an attribute that specifies the condition(s) for membership in the class
  type:  pm#unary_function_type  class of functions requiring a single argument; if R is functional, then if R(x -> y) and P(x -> z) then y=z
  type:  pm#partial_valued_relation_type  relation type that is not a total_valued_relation_type, i.e. just in case assigning values to every argument position except the last one does not necessarily mean that there is a value assignment for the last argument position; note that, if a sumo#relation is both a partial_valued_relation and a single_valued_relation, then it is a partial function
  supertype:  pm#relation_from_class (rdfs#class,*)
     supertype:  pm#relation_from_type (pm#type,*)  type of relations from a concept/relation type, i.e. in RDFS terminology, from a class or a property
        supertype:  pm#relation_from_collection (pm#collection,*)
           supertype:  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
              >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
           supertype:  pm#what_relation (*)
              supertype:  pm#wh-/how_relation (*)  this type permits to categorize relations according to the usual who/what/why/where/when/how questions ; this is a traditional but very subjective and ineffective way of categorizing relations 
                 >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type