Relation sumo#exhaustive_decomposition (class,class+)  an exhaustive_decomposition of a class C is a set of subclasses of C such that every instance of C is an instance of one of the subclasses in the set; note:  this does not necessarily mean that the elements of the set are disjoint (see sumo#partition - a partition is a disjoint exhaustive decomposition)
  supertype:  relation_to_another_class (pm)
  instance of:  predicate_type (pm)  variable_arity_relation_type (pm)
  related_to:  union_of
  subtype:  partition (class,class+)  a partition of a class C is a set of mutually disjoint classes (a subclass partition) covering C; each instance of C is instance of exactly one of the subclasses in the partition