Relation pm#subtype__subtype_or_equal (type,type) subtype links should actually be strict subtype links or not much checking can be done
supertype: specializing_type
inverse: supertype
equal: subsumes (pm)
subtype: strict_subtype (type,type) the '>' link in the FT notation
subtype: properly_subsumes_leaf__PSBL (type,type) the 2nd type is a leaf type properly subsumed by the 1st type
subtype: subsumes_leaf__SBL (type,type) the 2nd type is a leaf type subsumed by the 1st type
subtype: properly_subsumes_leaf__PSBL (type,type) the 2nd type is a leaf type properly subsumed by the 1st type