Highway to the Danger Zone
Marcus Kracht · Journal of Logic and Computation · 1995
Abstract This paper shows that: (i)there are quite simple methods for obtaining undecidability results in modal logics with more than one operator; and (ii) there are standard methods of simulating polymodal logics by monomodal logics which allow us to transfer the undecidability results of (i) to monomodal logics.