An Implmentation of a Free-variable Tableaux for KLM Preferential Logic P of Nonmonotonic Reasoning: the Theorem Prover FreeP 1.0

We present FreeP 1.0, a theorem prover for the KLM preferential logic P of nonmonotonic reasoning. FreeP 1.0 is a SICStus Prolog implementation of a free-variables, labelled tableau calculus for P, obtained by introducing suitable modalities to interpret conditional assertions. The performances of FreeP 1.0 are promising. FreeP 1.0 can be downloaded at http:// www.di.unito.it/ ∼pozzato/FreeP 1.0.