Universität des Saarlandes
Is there a link between Gabbay-style rules, modal languages with nominals, and labelled deduction? It seems there should be: though they differ in many ways, all share the idea that state-names are important in modal deduction. I shall show how to move from a Gabbay-style rule to labelled deduction via the basic hybrid language. I finish with a discussion of the place of state-names in modal logic.