Re: SWRL first-order logic
What would motivate anyone to use such a verbose representation?
Clearly, even using Lisp-like XML expressions, it would be easy to
find a more compact one.
JMHO,
Rich
John F. Sowa wrote:
> The folks who brought us RDF, OWL, RuleML, and SWRL,
> have now given us a version of first-order logic
> called SWRL FOL:
>
> http://www.daml.org/2004/11/fol/proposal
> A Proposal for a SWRL Extension to First-Order Logic
>
> Following is an example of "a simple, nonsensical assertion"
> in that report expressed in the XML notation for SWRL FOL:
>
> <Assertion owlx:name="Example">
> <owlx:Annotation>
> <owlx:Label>Example Rule for Expository Purposes</owlx:Label>
> </owlx:Annotation>
> <Forall>
> <ruleml:Var type="Person">x1</ruleml:Var>
> <ruleml:Var type="Parent">x2</ruleml:Var>
> <ruleml:Var type="Person">x3</ruleml:Var>
> <ruleml:Var type="xsd:int">x4</ruleml:Var>
> <And>
> <swrlx:individualPropertyAtom swrlx:property="hasParent">
> <ruleml:Var>x1</ruleml:Var>
> <ruleml:Var>x2</ruleml:Var>
> </swrlx:individualPropertyAtom>
> <swrlx:individualPropertyAtom swrlx:property="hasBrother">
> <ruleml:Var>x2</ruleml:Var>
> <ruleml:Var>x3</ruleml:Var>
> </swrlx:individualPropertyAtom>
> <swrlx:datatypePropertyAtom swrlx:property="hasAge">
> <ruleml:Var>x2</ruleml:Var>
> <ruleml:Var>x4</ruleml:Var>
> </swrlx:datatypePropertyAtom>
> </And>
> </Forall>
> </Assertion>
>
> Following is a translation of that assertion into four
> other notations for FOL:
>
> 1. Controlled English:
>
> For every person x1, parent x2, person x3, integer x4,
> the person x1 has the parent x2 as parent,
> the parent x2 has the person x3 as brother,
> and the parent x2 has the integer x4 as age.
>
> 2. Typed predicate calculus, limited to ASCII character set:
>
> (A x1:person)(A x2:parent)(A x3:person)(A x4:integer)
> (hasParent(x1,x2) & hasBrother(x2,x3) & hasAge(x2,x4))
>
> 3. Knowledge Interchange Format (KIF):
>
> (forall ((?x1 person) (?x2 parent) (?x3 person) (x4 integer))
> (and (hasParent ?x1 ?x2) (hasBrother ?x2 ?x3) (hasAge ?x2 ?x4)))
>
> 4. Conceptual Graph Interchange Format (CGIF):
>
> [Person: @every*x1] [Parent: @every*x2] [Person: @every*x3]
> [Integer: @every*x4] (hasParent ?x1 ?x2) (hasBrother ?x2 ?x3)
> (hasAge ?x2 ?x4)
>
> I agree with the authors that the example is nonsensical.
>
> John Sowa
>