W3C Rule Interchange Format (RIF) Advances to Proposed Recommendation
Members of the W3C Rule Interchange Format (RIF) Working Group have
published six Proposed Recommendation specifications. Together, they allow
systems using a variety of rule languages and rule-based technologies to
interoperate with each other and with Semantic Web technologies. Public
review is invited through June 08, 1020. The RIF Working Group has also
published a new version of "RIF Test Cases", and three other Working Drafts:
"RIF Overview", "RIF Combination with XML Data", and "OWL 2 RL in RIF". RIF
implementation information is also available, including thirteen
implementation reports received by the WG.
Three of the drafts define XML formats with formal semantics for storing and
transmitting rules: (1) The "RIF Production Rule Dialect (PRD)"
is designed for the kinds of rules used in modern Business Rule Management
systems. (2) The "RIF Basic Logic Dialect (BLD)" is a foundation for Logic
Programming, classical logic, and related formalisms.
(3) The "RIF Core Dialect" is the common subset of PRD and BLD, useful when
having a ubiquitous platform is paramount. The other drafts include:
(4) "RIF Datatypes and Builtins (DTB)" specifies the datatypes and standard
operations (modeled on XPath Functions) available in all RIF dialects (5)
"RIF RDF and OWL Compatibility" specifies how RIF works with RDF, RDFS, OWL
1, and OWL 2. (6) "RIF Framework for Logic Dialects (FLD)" provides a
mechanism for specifying extended dialects, beyond BLD, when more expressive
power is required...
The approach taken by the Working Group was to design a family of languages,
called dialects, with rigorously specified syntax and semantics.
The family of RIF dialects is intended to be uniform and extensible. RIF
uniformity means that dialects are expected to share as much as possible of
the existing syntactic and semantic apparatus. Extensibility here means that
it should be possible for motivated experts to define a new RIF dialect as a
syntactic extension to an existing RIF dialect, with new elements
corresponding to desired additional functionality. These new RIF dialects
would be non-standard when defined, but might eventually become standards.
Because of the emphasis on rigor, the word format in the name of RIF is
somewhat of an understatement. RIF in fact provides more than just a format.
However, the concept of format is essential to the way RIF is intended to be
used. Ultimately, the medium of exchange between different rule systems is
XML, a format for data exchange.
Recognizing that RIF rules should be able to interface with RDF and OWL
ontologies, the RIF Working Group has also defined the necessary concepts to
ensure compatibility of RIF with RDF and OWL. RIF, RDF, and OWL are exchange
languages with dissimilar syntaxes and semantics. How, then, should RIF
rules refer to RDF and OWL facts, and what is the logical meaning of the
overall language? RIF-RDF and OWL Compatibility defines just that. The basic
idea is that RIF uses its frame syntax to communicate with RDF/OWL. These
frames are mapped onto RDF triples and a joint semantics is defined for the
Next steps beyond moving to Recommendation status include extending RIF
semantics for complex event processing and more deeply integrated
reactiveness beyond production rules.?RuleML has been developing proposals
for new dialect(s), including Reaction RuleML, that addresses these
additional needed features.??
To learn more about RIF you probably want to start with:
and a FAQ: