- From: Daniel Elenius <elenius@csl.sri.com>
- Date: Thu, 23 Jun 2005 09:51:13 -0700
- To: public-sws-ig@w3.org
Getting back to the original issue, I now think we should just do this: <Condition rdf:ID="AlwaysTrue" /> Done. This has the added advantage of being usable with any expression language. It requires the OWL-S processor to be aware of this special instance, but so does the previous version, so no difference there. Daniel Daniel Elenius wrote: > Now that SWRL-Conditions aren't literals anymore, the following, in > the 1.2 Expression.owl, makes that file > OWL Full (since we are "redefining rdf:nil"): > > <SWRL-Condition rdf:ID="AlwaysTrue"> > <rdfs:label>Always True</rdfs:label> > <rdfs:comment> > An empty AtomList always evaluates to true. Note that this is not > equivalent to specifiying no > precondition. Due to open-world semantics of OWL, it would not be > possible to distinguish > having no precondition from not knowing the precondition. We would > need to specify a > cardinality 0 restriction on precondition property to indicate that > there is no precondition > which would be also valid. > </rdfs:comment> > <expressionLanguage rdf:resource="&expr;#SWRL"/> > <expressionObject> > <swrl:AtomList rdf:about="&rdf;#nil"/> > </expressionObject> > </SWRL-Condition> > > An easy solution would be to move the AlwaysTrue instance to a > separate file, which would only be imported by OWL-S services that use > SWRL. That way other services could still stay in OWL DL. Perhaps a > little ugly to have a file with just one instance though. > > Daniel > > -- > [To unsubscribe to this list send an email to "majdart@bbn.com" > with the following text in the BODY of the message "unsubscribe > daml-process"]
Received on Thursday, 23 June 2005 16:51:19 UTC