RE: [TED] Core Overview Section and Validation Appendix Added

Hi Adrian and all, my comments are inlined, Harold


-----Original Message-----
From: Adrian Giurca [mailto:giurca@tu-cottbus.de] 
Sent: Tuesday, February 13, 2007 5:05 AM
To: Boley, Harold; Christian de Sainte Marie
Cc: RIF WG
Subject: Re: [TED] Core Overview Section and Validation Appendix Added

Dear all,
> Great, I have edited the two diagrams / (meta-)models to
> initialize the Overview (Arch) Section:
>
> http://www.w3.org/2005/rules/wg/wiki/Core/Overview
>
>   

Looking to the RIF Core metamodel (the MOF/UML diagrams)  a number of 
questions arise:

    * The existent BNF and the actual MOF/UML metamodel are NOT
      equivalent. For example the definition of equality (Equal):  in
      the MOF model  equality orders the terms implied (by using roles
      /lhs /and /rhs/) but in the BNF (Equal      ::= TERM '=' TERM) no
      order is imposed. Lets try from the beginning to be more precise
      in such cases. I believe that BNF must align with the MOF abstract
      syntax.

The BNF is stripe-skipped, thus uses XML's natural order instead of most
roles (however, Equal is commutative, anyway).

    * Why we need the roles /formula/ and /declare/? How are they 
      specified in the BNF?

We don't need them if we want to be stripe-skipped even in the model
(see above).

    * Interesting, the last document of Core  Positive Conditions 
      contains now in the BNF two productions for /Atom /and /Expr /even
      they are the same in content. This  separate de facto  atoms from
      functions.

This is clearer, and simplifies possible alignment with classical FOL.

    * I suppose in the past was a problem of multiple inheritance (/Expr
      /was inheriting from both /Atom /and /TERM/) which creates
      troubles for tools to generate XMI, but in the MOF specification
      this is NOT restricted.

See above.

    * The naming of classes/roles are not appropriate. Why /arg /and not
      /arguments/?

No problem, in my experience, or in (X)HTML and MathML.

Thanks,
Adrian

Received on Tuesday, 13 February 2007 13:10:12 UTC