Abstract. The Rule Interchange Format Production Rule Dialect (RIFPRD) is a W3C Recommendation to define production rules for the Semantic Web, whose semantics is defined operationally via labeled terminal transition systems. In this paper, we introduce a declarative logical characterization of the full default semantics of RIF-PRD based on Answer Set Programming (ASP), including matching, conflict resolution and acting. Our proposal to the semantics of RIF-PRD enjoys several features. Being based on ASP, it enables a straightforward integration with Logic Programming rule based technology, namely for reasoning and acting with ontologies. Then, its full declarative logical character facilitates the investigation of formal properties of RIF-PRD itself. Furthermore, it turns out that our characterization based on ASP is flexible enough so that new conflict resolution semantics for RIF-PRD can easily be defined and encoded. Finally, it immediately serves as the declarative specification o...