Dear Doron, As I have told you earlier, I still think that our proof of chapter 8 is slightly easier than yours : At the very end, you need one additional summation which we do not have to use, because our variable t appears only for the vignette number 1. In other words, we use one more symmetry, and linearity of expectation, in order to avoid one summation. You can read the chapter 8 without reading anything else on : http://math.univ-lyon1.fr/~lass/articles/pub5coll.html http://math.univ-lyon1.fr/~lass/articles/pub5collres.pdf