RuleML Use Case ChemXelem
The Periodic System of the Elements

The Chemical XML Elements (ChemXelem) use case is the result of generating RuleML 0.89 from Relfun. ChemXelem is realized in three steps. First, the Relfun source in Prolog syntax is modified to obtain a version translatable into the current first-order RuleML 0.89. Second, after automatically relationalizing it within Relfun, an RFML (Relational-Functional Markup Language) version is obtained via Relfun's "style xml" option (XML version 1). Third, a RuleML version of the knowledge base is generated by automatic transformation via an XSLT Stylesheet (XML version 2). The validated RuleML result is then fed into the Java-based RuleML implementation of Object-Oriented jDREW BU to obtain all facts (and specialized rules) that can be derived bottom-up. The Periodic System of the Elements thus is a major use case of RuleML knowledge bases generated from a non-XML source and running in OO jDREW.

The original Relfun file (below) included higher-order features which had to be replaced. This allows the ChemXelem RuleML generated later to be parsed by the OO jDREW reasoning engine.

The RFML version of ChemXelem (below) is generated from the chemxelem.rfp source by following these steps:

The Relfun syntax is converted into RuleML using the rfml2ruleml089.xslt stylesheet which has been adapted from an earlier stylesheet for mapping a Hornlog RFML program into an older version of a RuleML rulebase. The new stylesheet is designed to map RFML into RuleML 0.89.

The resulting chemxelem.ruleml (below) is valid w.r.t. the Hornlog with equality sublanguage.

The RuleML facts and rules can be executed bottom-up with the OO jDREW BU Engine.