Thank you, apfelmus. That was a wonderful explanation; the debit method in [1] finally makes sense.
[1]: Chris Okasaki. Purely Function Data Structures. http://www.cs.cmu.edu/~rwh/theses/okasaki.pdf _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe