# Rule Interchange Format

## Contents

## 1 Definition

The **Rule Interchange Format (RIF)** refers to a series of W3C formats to define various kinds of rule systems.

## 2 RIF Framework for Logic Dialects (RIF-FLD)

The RIF Framework for Logic Dialects (RIF-FLD) is a formalism for specifying all logic dialects of RIF, including the RIF Basic Logic Dialect [RIF-BLD]. It is a logic in which both syntax and semantics are described through a number of mechanisms that are commonly used for various logic languages, but are rarely brought all together. Amalgamation of several different mechanisms is required because the framework must be broad enough to accommodate several different types of logic languages and because various advanced mechanisms are needed to facilitate translation into a common framework. RIF-FLD gives precise definitions to these mechanisms, but allows certain details to vary. The design of RIF envisages that future standard logic dialects will be based on RIF-FLD. Therefore, any logic dialect being developed to become a stardard should either be a specialization of FLD or justify its deviations from (or extensions to) FLD.

## 3 RIF Production Rule Dialect

The RIF Production Rule Dialect document specifies the production rule dialect of the W3C rule interchange format (RIF-PRD). Production rules are rules with an "if" part and a "then" part. The "if" part, also called a "condition", is like the condition part of logic rules (as covered by the basic logic dialect of the W3C rule interchange format, RIF-BLD). The "then" part of production rules may contain actions, unlike the conclusion of logic rules that may contain only a logical statement. Actions can modify the knowledge base and have other side-effects.

See also production system.

## 4 RIF Basic Logic Dialect

The RIF Basic Logic Dialect specification develops RIF-BLD (the Basic Logic Dialect of the Rule Interchange Format). From a theoretical perspective, RIF-BLD corresponds to the language of definite Horn rules with equality and a standard first-order semantics.

## 5 Links

- W3C RIF Working Group (includes links for current drafts and recommendations).