Re: RDF Semantics: corrections(was: Re: RDF Semantics: two issues, connected to OWL)

>[Pat, I'm cc'ing www-archive as it's easier that way to point back]

OK <snip>

>  > Was there a particular question you had that I
>>  can focus on?
>Well, the backbround was an asking of your opinion
>about the last message of last year in www-archive
>Is there an aternative way of *proving* inconsistencies ??
>(our usage of log:inconsistentWith is what
>euler uses for the OWL test cases and also
>in some observer component that we test)

You asked there if this misuses anything. I don't think so.  All of 
these should logically be equivalent, but the exigencies of search 
might make some more effective than others:

A inconsistentWith B

(A and B) entails (false)

  where 'false' could be any explicit contradiction, in principle, but 
of course you would need a strongly complete system to be sure of 
getting every possible contradiction actually derivable, so should 
likely choose a single representative impossiblity-indicator such as 
(P and not P).

(A and B) entails not(A)

C: (A consistentWith B)
not C

Not sure if this is any help....


Oh, PS: proving inconsistencies. The only real technique is to derive 
an explicit contradiction, like the null clause in resolution. The 
'xml clash' thingie in RDFS was an example closer to home. You have 
to figure out the ways that inconsistencies can arise, in practice, 
and kind of nudge your search engine in those directions.

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Received on Thursday, 15 January 2004 18:48:13 UTC