[Xesam] abstract properties?

[Jamie McCracken]

On Thu, 2008-02-14 at 03:15 +0200, Evgeny Egorochkin wrote:
> Hi guys,
> 
> This is in response to the lengthy discussion on #xesam that happened while I 
> was sleeping:
> 
> >(22:35:51)  kamstrup:  in other words a field is abstract if and only if it 
> has children 
> >(22:36:17)  jamiemcc:  yes and is not used in searches 
> >(22:36:30)  kamstrup:  also meaning that third parties can not extend fields 
> which does not have any children in the Xesam onto 
> >(22:36:45)  kamstrup:  moreover I also think we agreed that you can not 
> assign any value to an abstract field 
> >(22:36:54)  kamstrup:  (maybe obvious) 
> >(22:36:57)  jamiemcc:  yes 
> >(22:37:12)  kamstrup:  good, I think we agree then 
> >(22:37:15)  jamiemcc:  abstract are like intermediate classes 
> >(22:37:22)  kamstrup:  yes 
> >(22:37:31)  jamiemcc:  they ar enot used directly but instead are always 
> inherited from 
> >(22:37:36)  kamstrup:  only leaf nodes of the onto can contain values 
> 
> The benefits of this approach:
> 
> >(22:54:46)  kamstrup:  and having this as a restriction in Xesam does not 
> >render us incompatible with Nepo
> 
> This renders xesam incompatible with most if not any rdfs based approaches. 
> xesam->rdfs_derivative mapping is ok but it breaks in the opposite direction.
> 

since when was full rdfs compatibility a necessity?

xesam is supposed to be a subset of rdf (at least that was my
understanding) 

If abstract fields are flawed then you need to demonstrate with suitable
examples why. 


jamie