The W3C Rule Interchange Format (RIF) Working Group recently published "Last Call" drafts of two of its specifications:

   - "RIF Basic Logic Dialect" (BLD) specifies an XML format for rules

     at an intermediate expressive power.  The language is roughly

     Horn rules with URIs, datatypes, and builtins.  This goes beyond

     datalog (it has function terms), it but does not provide any kind

     of negation.   (Various forms of negation, and other features,

     are expected to be provided by dialects which extend BLD, to be

     published in the future.)

     http://www.w3.org/TR/rif-bld/

   - "RIF RDF and OWL Compatibility" explains and specifies how RIF

     rulesets are to be used in combination with RDF and OWL.

     http://www.w3.org/TR/rif-rdf-owl/

LAST CALL IS THE KEY TIME FOR EXTERNAL REVIEW.  The designs are essentially complete (the Working Group believes the design work is done), but things can still be changed in response to external input.

Additionally, input on editorial issues (especially pointing out

ambiguities) is always welcome.

In addition to these Last Call documents, the Working Group has published four other drafts:

   - RIF Production Rule Dialect (PRD) specifies an XML format for the

     exchange of production rules.  PRD and BLD are expected to be the

     basis of the two main dialect-branches, with RIF Core being the

     things in common between the two.  (We have not yet published a

     document expressing that intersection, but it can be inferred

     from the PRD and BLD specifications.)  This is a first public

     working draft.  This is an exellent time to comment on the

     general direction of the language, and give feedback on all the

     issues mentioned as Editor's Notes in the document.

     http://www.w3.org/TR/rif-prd/

   - RIF Framework for Logic Dialects (FLD) and RIF Datatypes and

     Builtins (DTB) provide common elements for specific dialects to

     use.

     http://www.w3.org/TR/rif-fld/

     http://www.w3.org/TR/rif-dtb/

   - RIF Uses Cases and Requirements (UCR), last published about two

     years ago, has been simplified and now has examples written in

     the PRD and BLD presentation syntaxes.  The examples can be

     hidden or revealed using Javascript controls.

     http://www.w3.org/TR/rif-ucr/

Feedback on all these documents should be sent to:

      public-rif-comments@w3.org

All comments (and responses to them) will be available at the public

archive:

      http://lists.w3.org/Archives/Public/public-rif-comments/

Please comment by 19 September so we have time to address your comments in incorporate any changes into our next round of publications.

Best,

Adrian Paschke