FreeP 1.0 user manual Download: http://www.di.unito.it/~pozzato/FreeP%201.0/index.html Kraus, Lehmann and Magidor (KLM) proposed a formalization of non-monotonic reasoning that was early recognized as a landmark. FreeP 1.0 is a theorem prover implementing free- variables tableaux calculi for the Preferential logic P of KLM framework. It is written in SICStus Prolog and also comprises a GUI written in Java. How to use FreeP 1.0 KLMLean 2.0 comprises a graphical interface written in Java. One can prove if a formula can be derived by a knowledge base by: - putting formulas in the check boxes representing the knowledge base - write the formula F to be checked in the suitable text box. Then, the user has to click the “PROVE” button and the response will be written on the righ-down corner. If the formula F follows from the knowledge base, FreeP offers two alternatives, that the user can select by clicking suitable buttons located under the response: - the closed tableau found by the Prolog engine can be displayed in a graphical window; - the closed tableau found by the prover is transalted into a latex source file, to be compi- led in order to obtain a .pdf/.ps of the closed tableaux.