Working Draft 11 May 2004

This version: version: Boley, NRC.


A presentation, shorthand, and exchange syntax is described that integrates Prolog's positional and F-logic's slotted syntaxes for representing knowledge (facts and rules) in the Semantic Web. This positional-slotted (POSL) language accomodates various assertional-logical and object-centered modeling styles, yet strives for maximum conciseness and orthogonality. After an introduction, the document covers POSL selectors, unification, webizing, typing, and implementation. Webizing takes up and extends the use of URIs in N3. For humans, the POSL language is faster to write and easier to read than any XML syntax. However, since a parser and a generator map the POSL syntax to Object-Oriented RuleML and back, the machine advantages of XML can be preserved.


Said Tabet and the RuleML Initiative as well as Sandro Hawke from W3C provided valuable feedback during the evolution of this document. The Joint Committee, especially Mike Dean and Benjamin Grosof, encouraged me to present earlier versions. In several telephone conferences the Joint Committee gave valuable feedback. In particular, Sandro Hawke and Pat Hayes helped shaping, respectively, sections 2 and 3 of the document through their questions. Bruce Spencer supported the development of OO RuleML, its implementations, as well as the POSL language. Marcel Ball and Stephen Greene gave valuable hints and performed various OO RuleML and POSL implementations. Michael Sintek helped me laying the groundwork of this Prolog/F-logic merger. The sponsoring of this work by the National Research Councilis also gratefully acknowledged.