leanK 2.0 implements an extension of the “Free Variable Tableaux for Propositional Modal Logics” reported by us in . It performs depth first search and is based upon the original leanTAP prover of Beckert and Posegga . Formulae annotated with labels containing variables capture the universal and existential nature of the box and diamond modalities, respectively, with different variable bindings closing different branches. Prolog’s built-in clause indexing scheme, unification facilities and built-in backtracking are used extensively.
- 1.Bernhard Beckert and Rajeev Goré. Free Variable Tableaux for Propositional Modal Logics. In Proceedings, International Conference on Theorem Proving with Analytic Tableaux and Related Methods, Pont-a-Mousson, France, pages 91–106. Springer, LNCS 1227, 1997.Google Scholar