A NEW DECISION METHOD FOR INTUITIONISTIC LOGIC BY 3-VALUED NON-DETERMINISTIC TRUTH-TABLES

Abstract

Kurt Gödel proved that it is not possible to characterize Intuitionistic Propositional Logic (IPL) by means of finite and deterministic truth-tables. After extending the same result with respect to non-deterministic matrices, we provide a semantical characterization of IPL by means of a 3-valued non-deterministic matrix with a restricted set of valuations. This structure allows to define an algorithm to delete unsound rows from the non-deterministic truth-tables generated for each formula, which constitutes a new and very simple decision procedure for IPL. This method can be seen as truth-tables in a broader sense, and a way to overcome Gödel's limiting result.