HTab: a Terminating Tableaux System for Hybrid Logic

Abstract

Hybrid logic is a formalism that is closely related to both modal logic and description logic. A variety of proof mechanisms for hybrid logic exist, but the only widely available implemented proof system, HyLoRes , is based on the resolution method. An alternative to resolution is the tableaux method, already widely used for both modal and description logics. Tableaux algorithms have also been developed for a number of hybrid logics, and the goal of the present work is to implement one of them. In this article we present the implementation of a terminating tableaux algorithm for the hybrid logic H ( @ , A ) . The performance of the tableaux algorithm is compared with the performances of HyLoRes , HyLoTab (a system based on a different tableaux algorithm) and RacerPro . HTab is written in the functional language Haskell, using the Glasgow Haskell Compiler (GHC). The code is released under the GNU GPL and can be downloaded from http://hylo.loria.fr/intohylo/htab.php .