  It transpires the mathematics is a lot simpler if, instead of assuming time is continuous, time is taken to be discrete. Thus we now assume that \(t = 0,1,2,\ldots\) . Assume also that intergenerational well-being at \(t = 0\) can be measured in terms of a numerical function \(V\). The idea is to require the function, which is defined on infinite well-being streams, to satisfy properties that reflect ethical directives.