Hypersequent calculi for non-normal modal and deontic logics: Countermodels and optimal complexity

Tiziano Dalmonte, Björn Lellmann, Nicola Olivetti +1

We present some hypersequent calculi for all systems of the classical cube and their extensions with axioms $T$, $P$, $D$, and, for every $n\ge 1$, rule $R{D}_n^{+}$. The calculi are…