For a generalised pareto cdf does not exist in closed form. What is the meaning of this closed form over here?
I guess closed form here means that we don't have a 'well defined expression' for CDF of Generalised Pareto as we have for two parameter pareto version. In other words, its cdf doesn't exist and we can't simply put values of x and get the result! We have to look at table values or use some computer package for it.
