[sc34wg3] supertype-subtype

Patrick Durusau sc34wg3@isotopicmaps.org
Fri, 15 Jul 2005 12:49:57 -0400


The note in 7.3 The supertype-subtype relationship, reads:

"Loops in this relationship are allowed, and should be interpreted to 
mean that the sets of instances for all types in the loop are the same. 
This does not, however, necessarily imply that the types are the same."

Ok, so B is a subtype of A, B is a subtype of A. (Assuming compliance 
with the other rules.)

But, I keep sticking at: "...sets of instances for all types in the loop 
are the same."

Do you mean "the same" for purposes of comparison on the type property?

I have tried to read it several ways and can only assume that "are the 
same" assumes some context for application.

Hope you are having a great day!


Patrick Durusau
Chair, V1 - Text Processing: Office and Publishing Systems Interface
Co-Editor, ISO 13250, Topic Maps -- Reference Model
Member, Text Encoding Initiative Board of Directors, 2003-2005

Topic Maps: Human, not artificial, intelligence at work!