some comments Re: warning label

From: Benjamin Grosof (
Date: 10/07/03

  • Next message: Peter F. Patel-Schneider: "Re: OWL Rules proposal"
    Hi folks,
    Some quick comments:
    - good first cut overall - thanks Mike!
    - the expressiveness limitations of current DLP include prohibition of 
    existentials or min-cardinality in a rule head, and correspondingly
    in a DL subsumption axiom's superclass expression (and a similar 
    dual/equivalent prohibition of universals or max-cardinality in the rule 
    body / DL-subclass).   See the DLP paper for details and discussion.
    - tools under development include SweetOnto (OWL -> RuleML V0.8) developed 
    by Boris Motik et al, based on the DLP paper.
    - we should augment and strengthen the warning a bit to explain that 
    restricting to DLP will ensure compatibility with
    extending expressively to LP with NAF/courteous/nonmon and/or with 
    procedural attachments (e.g., Situated Courteous LP)
    cf. currently commercially important (CCI) rule systems, but using the 
    above LP-inexpressible OWL features (existentials etc.) will
    likely/possibly cause significant practical problems wrt such compatibility
    - we should clarify the warning to include both (and distinguish between) 
    uses/users oriented towards extending OWL and uses/users  oriented towards 
    extending CCI/LP rule systems cf. more expressive RuleML.
    I'll aim to do a proper editing job soon but probably won't be able to get 
    to it today (pretty busy in a happy way with some family stuff...).
    >X-Sieve: CMU Sieve 2.2
    >Subject: warning label
    >Date: Sun, 05 Oct 2003 15:40:48 -0700
    >From: Mike Dean <>
    >X-Spam-Score: 2.4
    >X-Spam-Level: ** (2.4)
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    >As I promised during Tuesday's telecon, here's the first
    >draft of a "warning label" intended as a new section in [1].
    >Additions, corrections, and other suggestions are welcome.
    >         Mike
    >6.0  Usage Suggestions
    >At least in the near term until OWL reasoners begin to
    >support OWL Rules directly, users who want to maximize
    >interoperability with existing rule engines and OWL
    >ontologies encoded in RDF/XML may want to limit their
    >classAtoms to use named classes defined in the same OWL XML
    >file or external OWL XML or RDF/XML documents, e.g. use
    >   <owlx:classAtom>
    >     <owlx:Class owlx:name="#PhysicianChild"/>
    >     <owlx:Variable owlx:name="x1"/>
    >   </owlx:classAtom>
    >   <owlx:Class owlx:name="PhysicianChild">
    >     <owlx:IntersectionOf>
    >       <owlx:Class owlx:name="#Person"/>
    >       <owlx:ObjectRestriction owlx:property="#hasParent"/>
    >         <owlx:someValuesFrom owlx:class="#Physician"/>
    >       </owlx:ObjectRestriction>
    >     </owlx:IntersectionOf>
    >   </owlx:Class>
    >rather than
    >   <owlx:classAtom>
    >     <owlx:Class owlx:name="PhysicianChild">
    >       <owlx:IntersectionOf>
    >         <owlx:Class owlx:name="#Person"/>
    >         <owlx:ObjectRestriction owlx:property="#hasParent">
    >           <owlx:someValuesFrom owlx:class="#Physician"/>
    >         </owlx:ObjectRestriction>
    >       </owlx:IntersectionOf>
    >     </owlx:Class>
    >     <owlx:Variable owlx:name="x1"/>
    >   </owlx:classAtom>
    >as this allows simpler translation of atoms into other rule
    >Users anticipating use of their rules with prioritized
    >conflict resolution, defaults, procedural attachments, or
    >other advanced features of rule engines based on Logic
    >Programming may want to limit their classAtoms to use named
    >classes within the expressiveness of Description Logic
    >Programs [Grosof 2003].  This limits [Benjamin fill in
    >An example of an OWL class outside the expressiveness of
    >Description Logic Programs is
    >   <owlx:Class owlx:name="Orphan">
    >     <owlx:IntersectionOf>
    >       <owlx:Class rdf:name="#Person"/>
    >       <owlx:ObjectRestriction owlx:property="#hasParent"/>
    >         <owlx:allValuesFrom owlx:class="#Deceased"/>
    >       </owlx:ObjectRestriction>
    >     </owlx:IntersectionOf>
    >   </owlx:Class>
    >because of the use of owl:allValuesFrom.  Use of such a
    >class within a classAtom may cause difficulties in future
    >versions of OWL Rules.
    >Development of theoretical foundations and algorithms to
    >more fully combine the results of Description Logic and
    >Logic Programming is an active area of research.  OWL Rules
    >is expected to grow as such research comes to fruition.
    >Tools to convert between OWL Rules and RuleML 0.8 [RuleML] are
    >being developed.
    >         Description Logic Programs:  Combining Logic
    >         Programs with Description Logic.  Benjamin Grosof,
    >         Ian Horrocks, Raphael Volz, Stefan Decker.  Proc.
    >         WWW2003, Budapest, May 2003.
    Prof. Benjamin Grosof
    Web Technologies for E-Commerce, Business Policies, E-Contracting, Rules, 
    XML, Agents, Semantic Web Services
    MIT Sloan School of Management, Information Technology group or

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