Relation owl#same_as (?,?)  MORE PRECISE TYPES THAN THIS ONE SHOULD BE USED
  supertype:  equal (pm)  "=" in KIF; true if the 1st argument is identical to the 2nd
  equal:  equivalent_to (owl)
  subtype:  same_type_as (type,type)
     subtype:  equivalent_class (class,class)  in WebKB, use the link '='
     subtype:  equivalent_property (binary_relation_type,binary_relation_type)  in WebKB, use the link '='
  subtype:  same_individual_as (?,?)