A Set-Theoretic Translation Method for Polymodal Logics Giovanna D'Agostino, Angelo Montanari, Alberto Policriti Abstract: The paper presents a settheoretic translation method for polymodal logics that reduces the derivability problem of a large class of propositional polymodal logics to the derivability problem of a very weak firstorder set theory \Omega. Unlike most existing translation methods, the one we proposed applies to any normal complete finitelyaxiomatizable polymodal logic, regardless if it is firstorder complete or if an explicit semantics is available for it. Moreover, the finite axiomatizability of \Omega makes it possible to implement mechanical proof search procedures via the deduction theorem or more specialized and efficient techniques. In the last part of the paper, we briefly discuss the application of set T resolution to support automated derivability in (a suitable extension of) \Omega.