Abstract

The paper investigates propositional modal languages which contain indexes referring to possible worlds. A basic possible worlds logic is defined, in which we can mimic standard conditions in the usual modal semantics on the behavior of possible worlds. Connections between modality and world-indexed sentences are then studied. A semantics in terms of 'possible worlds' is defined, and completeness results relative to special classes of models called 'mirror models' are proved. © 2011 Elsevier B.V., All rights reserved.