Relation sumo#subrelation (relation_type,relation_type)  if the common reading conventions of parameters had been respected, this type would have been named subclass_of; every tuple of the 1st argument (r1) is also a tuple of the 2nd argument (r2), i.e. if r1 holds for some arguments arg_1, arg_2, ... arg_n, then the r2 holds for the same arguments; a consequence of this is that a relation and its subrelations must have the same valence
  supertype:  supertype (pm)  in the FT notation, the '<' link is only used to connect to a "strict" supertype
  instance of:  binary_predicate_type (pm)  partial_ordering_relation_type (pm)
  equal:  genl_preds (sumo)
  subtype:  sub_property_of (binary_relation_type,binary_relation_type)  in WebKB, use the link '<'