Implementation and Evaluation of a Tableau Algorithm for the Guarded Fragment

Abstra t. In this paper we present Saga, an implementation of a tableau-based Satis ability Algorithm for the Guarded Fragment (GF). Satis ability for GF with nite signature is ExpTimeomplete and therefore intra table in the worst ase, but existing tableau-based systems for ExpTimeomplete des ription and modal logi s perform reasonably well for \realisti " knowledge bases. We implemented and evaluated several optimizations used in des ription logi systems, and our results show that, with an eÆ ient ombination, Saga an ompete with existing highly optimized systems for des ription logi s.