From POSL to d-POSL: Making the Positional-Slotted Language Defeasible

The Positional-Slotted Language (POSL) provides a human-oriented syntax for a subset of RuleML/XML. POSL is specified in EBNF and as an ANTLR grammar. A POSL<-->RuleML converter relieves users from writing RuleML in XML. Some rule engines (including OO jDREW) use POSL for rule and query editing. Defeasible RuleML (d-RuleML) permits the prioritization of rules and the presence of non-monotonicity. The current POSL 0.91 shall be upgraded to POSL 1.0 (crucial difference: separator between a variable and its type changed from ":" to "^^", e.g. from ?product:EBizProd to ?product^^EBizProd) and extended (with IRI namespace prefixes, built-in calls, etc.), in sync with RuleML 1.0.