Checking for orthant orderings between discrete multivariate distributions: An algorithm

We consider four orthant stochastic orderings between random vectors X and Y that have finitely discrete probability distributions in IRk. For each of the orderings conditions have been developed that are necessary and sufficient for dominance of Y over X. We present an algorithm that checks these conditions in an efficient way by operating on a semilattice generated by the support of the two distributions. In particular, the algorithm can be used to compute multivariate Smirnov statistics.