seperable utility functions are an alternate formulation of utility functions.
Let X={x1,p1;,..,;xn,pn}
v(x)=Sum(i=1,n,f(xi,pi))
where f(xi,pi)=u(xi)w(pi) with w(0)=0 and w(1)=1
Major problem:
if f(xi,pi+qi)>f(xi,pi)+f(xi,qi) it can be shown that you violate first order
stochastic dominance.