Hello. Haskells declarativity is really useful to transform mathematical models into data types and algorithms. In the context of a seminary I have dealt with equilibria concepts (especially Nash and Wardrop equilibrium) in loss networks. (based on "Non-cooperative routing in loss networks" by Altman et al.) Thereby I have noticed that some algorithms are very easy to implement in Haskell, e.g. the state space or the blocking probability. Surely these algorithms are not efficient, they should just do their jobs. On the other hand there are algorithms, too, which appear to be really hard and long winded to implement, e.g. the equilibria by itself. My question: Is there an elegant way of programming a numerical solver of problems like "given the conditions ... find a solution which minimizes/maximizes the following function ...". Presumably there is no such "way" in general, but maybe someone can give a hint, how to tackle these kinds of problems. Or maybe there are some libraries doing this job. Thanks in advance and best greetings. Steffen Mazanek