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Re: post-conditions in OWL files

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Wed, 27 Feb 2008 20:00:07 +0000
Message-Id: <696BE159-237D-4011-816D-031D4D1C4783@cs.man.ac.uk>
Cc: public-owl-dev@w3.org
To: Matthew Pocock <matthew.pocock@ncl.ac.uk>

Matthew,

It sounds like you (roughly) want something like unit tests. Well a  
bit more general than that, but it's similar in spirit.

I'd use annotations on the axioms. Then it's easy enough to flush out  
the ones that should be verified rather than the ones that should be  
used.  Since this is only a development time matter (i.e., I presume  
it doesn't matter to a shipping app that C subClassOf D is asserted  
rather than inferred...in fact, having the asserted one is way faster!)

I've been wanting this for a while...so maybe I'll cook something up.  
In particular, Matthew Horridge and I have been discussing a lint  
tool that looked at all the justificaitons for all the subsumptions  
and reported ones whose only explanation was the singleton set  
contain itself. So, for example, suppose in some ontology O, the set  
of justifications for C sub D was:
	{{C sub D}}

The lint tool would raise a fuss ("Hey, you're a lazy modeller,  
y'know?"). However, if the set were:

	{{C sub D}
	{C sub E. E sub D}}

It'd be fine.

Er..ok you say something weird I don't get:

"""Post-reasoning, for the ontology to be consistent, this assertion  
MUST be
satisfied. If not, then there is a problem. However, this is weaker  
in one
sense than asserting

subClass(uncle brother)

which would add this as a one of the input axioms of the reasoner,  
potentially
raising an inconsistency if this clashes with other axioms. The
inferredSubClass axiom would only raise inconsistency if it is not  
entailed
by the other axioms."""

Does this mean that if I had:

inferedSubClass(uncle, brother)
subClass(uncle, complementOf(brother)

and your other axioms, the ontology wouldn't be inconsistent? (That  
introduces non-monotonicity, which is a different game...)

Cheers,
Bijan.
Received on Wednesday, 27 February 2008 19:58:21 GMT

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