Hi all, I'm working my way through the lecture notes to the "Finally Tagless" course, available from: http://okmij.org/ftp/tagless-final/course/index.html As usual at every round of doing so, I think it's my 4th, I discover something new, something that hadn't occurred to me previously. This time it's a comment in the code of SerializeExt.hs -- * Tie up the knot fromTree = S.fix fromTreeExt -- One does use fix in real programs -- Now we can see the real benefit of using fix in real programs. -- The fixpoint combinator is NOT a mere curiosity about the fix-point combinator. I don't think I can deduce what he meant by that from the context alone, could somebody please enlighten me? I'm refering to the benefit of using the fix-point combinator in this particular scenario. Günther