Re: the precondition property in OWL-S 1.0

   [Monika Solanki, in re DAML-S spec]
   Currently in the 1.0 version of the process model, we have the following

     <owl:Class rdf:ID="Precondition" />
   - <owl:ObjectProperty rdf:ID="preCondition">
     <rdfs:domain rdf:resource="#Precondition" />
     <rdfs:range rdf:resource="#Condition" />
     </owl:ObjectProperty>

   Where, Condition is defined as,

   - <owl:Class rdf:ID="Condition">
     <rdfs:comment>This is a "place-holder" for now, which awaits further 
   work from the DAML/OWL community. An instance of Condition is a logical 
   formula that evaluates to true or false. Eventually we expect this to be 
   defined elsewhere, as part of a OWL extension allowing for logical 
   expressions.</rdfs:comment>
     </owl:Class>

   Somehow I am not able to grasp the utility of the property 
   "preCondition".  Since in this model, we have IOPEs as Classes, 
   therefore I believe all we need to do is make Precondition a subclass of 
   Condition.

    <owl:Class rdf:ID="PreCondition">
     <rdfs:subClassOf rdf:resource="#Condition" />
     </owl:Class>

   The property preCondition, introduces redundancy as it is ranging over 
   the class "Condition" anyways.

   Feedback appreciated in case I missed something.

You're right, as far as I can see.  The important property is
hasPrecondition, which connects a Condition to a
Process or Process step.  There is no reason for the class
Precondition to exist, let alone a property preCondition linking a
Precondition to a Condition (itself?).

-- 
                                             -- Drew McDermott
                                                Yale University CS Dept.

Received on Thursday, 6 November 2003 16:25:59 UTC