Relation sumo#geometric_distance__geometricdistance ()
  type:  pm#ternary_predicate_type__ternarypredicatetype  class of predicates that require exactly three arguments
  type:  pm#single_valued_relation_type  when an assignment of values to every argument position except the last one determines at most one assignment for the last argument position; not all single_valued_relations are total_valued_relations
  type:  pm#total_valued_relation_type  when there exists an assignment for the last argument position of the relation given any assignment of values to every argument position except the last one; note that declaring a relation to be both a total_valued_relation and a single_valued_relation means that it is a total function