 This is formalized by the formula \(\mathtt{@_a p}\) where the nominal \(\mathtt{a}\) stands for “it is five o’clock 15 November 2021” as above and where \(\mathtt{p}\) is an ordinary propositional symbol that stands for “it is raining”. It is the part \(\mathtt{@_a}\) of the formula \(\mathtt{@_a p}\) that is called a satisfaction operator. In general, if \(\mathtt{a}\) is a nominal and \(\mathtt{\phi}\) is an arbitrary formula, then a new formula \(\mathtt{@_a\phi}\) called a satisfaction statement can be built. The satisfaction statement \(\mathtt{@_a\phi}\) expresses that the formula \(\mathtt{\phi}\) is true relative to one particular point, namely the point to which the nominal \(\mathtt{a}\) refers.