## Dialogical modal logic (for T, B, S4 and S5). (Dialogische Modallogik (für T, B, S4 und S5).)(German)Zbl 1015.03026

The authors present proposals for extending the dialogical approach to logic, developed by P. Lorenzen and K. Lorenz for classical and intuitionistic logic, to the (classical and intuitionistic) normal modal logics T, B, S4, and S5. The introduced strategic tableaux strongly resemble M. Fitting’s indexed tableaux for modal logics. The presentation of the paper is mostly conceptual; no characterization proofs are given.

### MSC:

 03B45 Modal logic (including the logic of norms)

### Keywords:

dialogical logic; modal logic; strategic tableaux