Core] What Externals (Was: Re: RIF Core shortened)

Gary Hallmark wrote:
> 
> BTW, we discussed External(#) and External(##) several times but it 
> doesn't help because
> a. they aren't legal in BLD, thus BLD would have to change for these to 
> be in core
> b. we need "internal" # and ## rather than External to represent object 
> facts.

I think that this is not resolved (issue-78 [1]). And, what can be external is at risk in BLD; so, we do not even need to backtrack on Last Call to change our mind and allow any ATOMIC to be external.

Some membership and subclass facts are, really, external, and we must ask ourselves whether this need be reflected in the syntax of not.

<\chair's hat>
I believe that it may be useful to make the difference syntactic, to avoid ambiguity: after all, why forbid an application to modify an externally defined data model to specify an internally defined one that adds subclass relations? That would require the assertion of a subclass facts where both classes are part of the same externally defined data model (see also my other email about asserting # and ## [2]).

But then, how to determine, in a condition whether a test for a subclass relation is about the externally defined data model or the internally modified one? Wrapping the former test in an External would do the trick, I think.

And, of course, Externals cannot be asserted...

What do you think?

[1] http://www.w3.org/2005/rules/wg/track/issues/78
[2] http://lists.w3.org/Archives/Public/public-rif-wg/2008Nov/0111.html

<chair's hat>

Cheers,

Christian

Received on Tuesday, 18 November 2008 15:06:46 UTC