 Such descriptions are not easy to understand, nor convenient to work with. Montague (1973, 228) said, ‘it is probably more perspicuous to proceed indirectly’. For this purpose he introduced a language, called ‘intensional logic’. The operation described above is then represented by \(^{\wedge}\lambda t\lambda u[t = u\)]. The \(\lambda t\) says that it is a function that takes \(t\) as argument, likewise for \(\lambda u\). So \(\lambda t\lambda u[t = u\)] is a function which takes two arguments, and yields true if the arguments are equal, and otherwise false. The preceding \(^{\wedge}\) says that we consider a function from possible worlds and moments of time to the thus defined function.