Axiomatizing logics of finite Gödel-Kripke models

Abstract

We investigate completeness for modal Gödel logics with respect to finite Gödel-Kripke models, along with related aspects. It is well known that the logics studied in [4, 11] fail to be complete with respect to finite Gödel-Kripke models. We show that the natural candidate axiomatic extensions do not restore completeness, thereby resolving a 15 year open problem posed in the aforementioned works. We then provide new axiomatizations that are complete for finite models and characterize intermediate witnessing conditions that hold for the basic logics.