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RE: Consistency Checker

From: Peter Crowther <Peter.Crowther@networkinference.com>
Date: Tue, 14 Jan 2003 17:59:54 -0000
Message-ID: <3BE4D3F0FB726240966DEF40418472B5012C99@ni-lon-server1.ad.networkinference.com>
To: <www-webont-wg@w3.org>

> From: Jeremy Carroll [mailto:jjc@hplb.hpl.hp.com] 
> - the agreement in the IRC is for five consistency checkers:
>    Sound Lite/DL/Full
>    Complete Lite/DL
> But the first three are identical, so I have condensed them 
> to one thing.
> 
> Have I understood correctly, or is there some subtle 
> difference between an 
> incomplete OWL Lite consistency checker, and an incomplete OWL Full 
> consistency checker that I have missed?

They're not *necessarily* different, as a sound but incomplete reasoner
merely never has to say 'yes' when it should say 'no' and therefore can
always say 'no' --- Sean's idea of a pipe to /dev/null coming in again
:-).

However, they may be *practically* different.  It may be easier to write
a sound and relatively (but not fully) complete reasoner for Lite than
for Full, for example; but it may be easy to write a sound but
differently-incomplete reasoner for Full that doesn't do parts of Lite.
The easy stuff at a given level doesn't necessarily match the easy stuff
at 'easier' sublanguages.  So I'd expect to see a plethora of sound but
incomplete consistency checkers, and (hopefully!) some sound and
complete ones for Lite and DL.

Does that help, or have I done my usual water-muddying again?

		- Peter
Received on Tuesday, 14 January 2003 13:00:26 GMT

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