 follows directly by \(\textbf{Gen}\astQ\) and Cont∃. However, Prior (1967: 150) argues that there is still a robust way of expressing the intuitive contingency of an object \(x,\) viz., that \(x\)’s existence is not (strongly) necessary, i.e. (where \(\sfx\) denotes \(x\)), that \(\exists \sfy\, \sfy=\sfx\) is not true in all worlds: \(\neg\Box\exists \sfy\, \sfy=\sfx\). But in the context of Q this is equivalent to saying simply that \(\exists \sfy\, \sfy=\sfx\) is not n-statable, \(\neg\rS \exists \sfy\, \sfy=\sfx\). Accordingly, given  SDef,  we have: