Duzhin's Comment of June 13
July-07-11
2:18 PM
BTW, I found that any antisymmetric function of x,y,z which iz identically zero outside the plane x+y+z=0, satisfies the Klein relation and thus gives rise to a weight system. It is easy to find undecomposables among them, e.g.
E_{1,2,-3}+E_{1,3,-4}+E_{2,3,-5}
where each E_{a,b,c} stands for a function which is 1 on (a,b,c), +-1 on the permutations and 0 elsewhere.
Comment - on Jan 2, 2012 Duzhin emailed me that the above is wrong.