LegalRuleML proposed charter and XACML

Consider revising the charter to define the intended relationship of LegalRuleML to XACML (eXtensible Access Control Markup Language, http://www.oasis-open.org/committees/xacml).

While the surface syntax of the XACML policy language differs significantly from RuleML and other rule languages, XACML’s condition and _expression_ sublanguages are very nearly—if not equally—as expressive, since they were designed to handle complex business rules. XACML defines a large library of built-in functions (including higher-order set functions) for testing attribute values. The consequents of XACML rules are limited, syntactically, to “Permit” and “Deny”, but it is only a small abstraction to extend this to any binary choice, which covers a large range of legal rules: legal/illegal, guilty/not-guilty, fulfill/breach (a contract). A XACML decision can include an Obligation, which essentially makes XACML a full production rule system, since the obligation can specify any type of consequence (although XACML does not specify the meaning or execution of obligations).

XACML provides a built-in upper ontology that covers most common business and legal situations: Subject (actor, or principal), Action, and Resource (the thing being accessed or acted upon). This ontology (or set of Categories) is easily extensible. XACML defines all the syntactic and architectural machinery for describing subjects, actions, and resources by their attributes. This mechanism maps fairly directly to semantic web data representation idioms.

A XACML rendition of LegalRuleML would enable users to take advantage of off-the-shelf XACML policy engines and policy development tools.

I haven’t thought out all the possibilities for interoperability or cross-fertilization between LegalRuleML and XACML, but at first glance it seems there could be many mutual benefits. These could be investigated through formal or informal liaison between the two TCs.

Regards,

--Paul

oasis-charter-discuss message