Hi all, here I am again with my all time favorite unsolved problem: stack overflows. The advice I have received so far from the Haskell community (this list and #haskell) was to use strictness annotation or seq in most cases. And indeed it did help. It certainly helped when I used a data structure that I designed myself and a filling routine that I also wrote myself, thanks guys (and girls possibly, I mean I don't know). But sometimes neither of the 2 helps. Especially when you are using a brilliantly designed data structure such as IxSet, from happstack, originally HAppS. Since it's someone else code it's too late to add strictness annotation. Or the "core" insert that you have to use in your filling routine is lazy. In such cases you're just out of a luck. I have read about alternatives to the above mentioned techniques, CPS, Codensity-Monad and this http://wwwtcs.inf.tu-dresden.de/~voigt/mpc08.pdf in Blogs, Wikis and Papers, also on this mailing list a post called "stupid question #852". Well when I say alternatives I mean I *perceived* these techniques to be *meant* as alternatives, as a way to control evaluation order, or *force* evaluation. And this is my question: Am I barking up the wrong tree, is the purpose of these techniques actually not to force evaluation order? Günther