PSOA2TPTP: A Reference Translator for Interoperating PSOA RuleML with TPTP Reasoners

PSOA RuleML is a recently specified rule language combining relational and object-oriented modeling. In order to provide reasoning services for PSOA RuleML, we have implemented a reference translator, PSOA2TPTP, to map knowledge bases and queries in the PSOA RuleML presentation syntax (PSOA/PS) to the popular TPTP format, supported by many first-order logic reasoners. In particular, PSOA RuleML reasoning has become available using the open-source VampirePrime reasoner, enabling query answering and entailment as well as consistency checking. The translator, currently composed of a lexer, a parser, and tree walkers, is generated by the ANTLR v3 parser generator tool from the grammars we developed. We discuss how to rewrite the original PSOA/PS grammar into an LL(1) grammar, thus demonstrating that PSOA/PS can be parsed efficiently. We also present a semantics-preserving mapping from PSOA RuleML to TPTP through a normalization and a translation phase. We wrap the translation and querying code into RESTful Web services for convenient remote access and provide a demo Web site.