  and establish that factivity of \(w\), i.e.,  \(w : B \rightarrow B\) is not derivable from  \(\mathcal{S}\). Here is a possible world justification model  \(\mathcal{M}\) =  \((\mathcal{G} , \mathcal{R} , \mathcal{E} , \mathcal{V})\) in which  \(\mathcal{S}\)  holds but \(w : B \rightarrow B\) does not: