Reasoning about the semantic web using answer set programming

Abstract. The paper discusses some innovative aspects related to the integration of a framework based on Answer Set Programming in an Information Retrieval Agent, namely, the Global Search Agent. In order to improve the original system effectiveness, the GSA2 system introduces a new internal architecture based on a message-passing framework and on an ontology description formalism (WOLF, Web OntoLogy Framework), conceived in order to describe and make reasoning on “facts about the web and the user”. The role of a central intelligence is played by a reasoning system based on Answer Set Programming; it makes the Agent able to take independent decisions. The high expressive power of Answer Set Programming allows to describe, program and plan behaviors of the Agent easily and quickly, and to experiment with any (even future) Information Retrieval strategy. Both the System Architecture and WOLF are very general and reusable, and constitute a very good and interesting example of actual exploiting of Answer Set Programming for real applications.