[sc34wg3] TMCL 6.7 Overlap Declaration

Patrick Durusau patrick at durusau.net
Fri Jun 19 15:48:56 EDT 2009


Reading a bit further and I encountered:

> The |tmcl:overlap-declaration| is used to declare that the sets of 
> instances of two or more topic types are non-disjoint (that is, that 
> they may overlap). The default is that the instance sets of different 
> topic types are disjoint. 
Understand that having the distinction between disjoint and non-disjoint 
topic types is useful but wonder about the default being "...that the 
instance sets of different topic types are disjoint."

Particularly given the example of person as a topic type overlapping 


person overlapping author, editor, artist, illustrator, umpire, referee, 
chair, secretary, policeman, firefighter, driver, jockey, batter, 
pitcher, catcher, player, singer, musician, actor, actress, director, 
producer, composer, etc.

Not to mention all the other roles will commonly overlap.

Why not make the default that topic types overlap and provide the means 
to declare that particular types *are* disjoint?

Making the general rule the most common case seems like a better option 
to me.

Hope everyone is having a great day!


Patrick Durusau
patrick at durusau.net
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)

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