 Once again, assume that we have a set of possible worlds, \(W\), and we assume that we have a relation, \(R\), relating worlds to worlds, with the intention that \(Rij\) iff \(j\) is accessible to \(i\) (e.g., \(j\) is a world where everything true in \(j\) is possible relative to  \(i\).[41]  For brevity, we will call all worlds possible relative to \(i\), “\(i\)-accessible worlds” and denote them by \(R^i\). For the moment, no restrictions are placed on the relation \(R\). We can illustrate the truth-conditions for necessity, and possibility with obvious abbreviations, as follows: