 for \({\hK}\) the modal dual of K (i.e., \(\hK\psi := \lnot K\lnot \psi)\). This extended language \(\cL_{\left\{ [{\leq}], K \right\}}\) can also express a notion of strong belief, \(Sb \varphi\), semantically understood as true whenever all \(\varphi\)-worlds are strictly more plausible than all \(\lnot\varphi\)-worlds, and syntactically defined as 