Re: nonmon mapping and punning

On Mar 6, 2008, at 8:13 AM, Alan Ruttenberg wrote:

> I thought the issue wasn't in adding or removing one triple, but  
> rather the general truth maintenance issue. Namely you have rules  
> that depend on certain triples existence as antecedents. You don't  
> necessarily known when these rules fire, relative to when you need  
> to retract a statement. If adding something causes you to retract a  
> statement, then you want to also retract all triples that were  
> added based on rules which had the retracted triple as antecedent.
>
> The mechanism you refer to below is possibly adequate to retract a  
> triple (possibly because it isn't clear to me from the spec whether  
> triples added by a reasoner would trigger the event). But it isn't  
> adequate to retract the triples that were added as a result of  
> rules that fired based on it.

[snip]

I'm missing something...why would non-monness in the mapping force  
truth maintenance to be necessary? Or be any worse than any edit  
cycle? (E.g., I add something, I delete something...I have to update  
the classification and other cached entailments no matter what. If  
Jena is radically incompatible with this then it's impossible to use  
for editing applications or any application where the data might  
fluctuate. I can't believe that's true!  They have proposed update  
extension to SPARQL!

http://jena.hpl.hp.com/~afs/SPARQL-Update.html#sec_updateLanguage

Now, SPARQL is only for graph syntax (for want of a better phrase),  
not entailment defined, but it's hard to believe that HP's line is  
"Don't use sparql update with any Jena model that uses inference of  
any sort.")

(I feel like I've been through this discussion before, in the past,  
perhaps with Andy Seabourne in the DAWG times...or maybe it's just  
deja vu.)

(Perhaps Jeremy could clarify what HP thinks is going on, rather than  
the rest of us guessing?)

Cheers,
Bijan.

Received on Thursday, 6 March 2008 08:38:33 UTC