[Pellet-users] Getting the description

[Michael Smith]

On Mon, 2008-07-07 at 16:23 +0200, cbobed at unizar.es wrote:
> Michael Smith <msmith at clarkparsia.com> ha escrito:
> 
> > On Mon, 2008-07-07 at 00:54 +0200, cbobed at unizar.es wrote:
> >
> >> is there any way to obtain the simplified representation of an
> >> asserted concept? I mean, once I've asserted a hand-built concept into
> >> the knowledge base and running the classification process, I don't
> >> just want the equivalent concepts but the canonical representation of
> >> them. I've tried with the unfold but it doesn't give me the
> >> information I need.

> For example, given a concept defined as (A and (not (not B))), which  
> is clearly classified as equivalent to (A and B) I would like to get  
> the latter descrciption instead of the first one. Thanks in advance.

This is not directly supported by Pellet.  You may be able to meet your
goals by combining the unfold with a syntactic transformation, but
TBox.unfold isn't intended to be a public API call.

The example above shows one type of simplification, but its not clear
how you expect it to generalize to other descriptions.  There are three
distinct types of syntactic transformation offered in the distribution
if you are using the Pellet ATerm based API - see the javadoc for

ATermUtils.nnf
ATermUtils.normalize
ATermUtils.simplify

If you are using the OWLAPI - see the javadoc for

org.semanticweb.owl.normalform.NegationalNormalFormConverter


-- 
Mike Smith

Clark & Parsia