Relation pm#intransitive_relation (?,?)  this category only serves structuration purposes: it is instance of pm#intransitive_relation_type which is not instance of pm#class_of_inheritable_relation_type
  supertype:  binary_relation_with_particular_mathematical_property
  instance of:  intransitive_relation_type
  subtype:  inverse__reverse (binary_relation_type -> binary_relation_type)  for inverseOf(R,S) read: R is the inverse of S; i.e. if R(x,y) then S(y,x) and vice versa; in WebKB, use the link '-'
  subtype:  immediate_instance__immediateinstance (?,set_or_class)  if the common reading conventions of parameters had been respected, this type would have been named immediate_instance_of; an object is an immediate_instance of a set_or_class if it is an instance of the set_or_class and there does not exist a subclass of set_or_class such that it is an instance of the subclass
  subtype:  immediate_subclass__immediate_subclass_of (set_or_class,set_or_class)  the 1st argument is a subclass of the 2nd argument and there is no other subclass of the 2nd argument such that the 1st is also a subclass of the 2nd; in WebKB, use the link '<'
  subtype:  member (self_connected_object,collection)  a specialized common sense notion of part for uniform parts of collections; for example, each sheep in a flock of sheep would have the relationship of member to the flock
  subtype:  penetrates (object,object)  the 1st object is connected to the second along at least one whole dimension (length, width or depth)
  subtype:  element (?,?)
  subtype:  meets_temporally__meetstemporally (?,?)
  subtype:  parent (?,?)