Update to core/space.owl + References

[Michael Jewell]

Hi all!

I've updated our Space class to use equivalentClass to pull in the AKT
Location ontology Abstract-Space class instead of subclassing. This
means that we should now be able to treat any Abstract-Space subclass
(whether in OntoMedia or not) as an Entity, and I've also been able to
tidy up some of our properties a little.

For my next trick, I'd like to add refers-to and referenced-by as
properties on Expression. This is for cases such as 'Character A talks
about Character B' or 'Character A mentions Location C', as the referred
entities aren't strictly 'involved' in the event. Any
objections/suggestions to this? :)

Cheers,
Mike

[Paul Rissen]

Sounds good to me. Very useful for 'indirect' involvements in events.