S.V.Chmutov, S.V.Duzhin.
An upper bound for the number of Vassiliev knot invariants.
We prove that the number of independent Vassiliev knot invariants
of order $n$ is less than $(n-1)!$ --- thus strengthening the
a priori bound $(2n-1)!!$.
The paper starts with a short introduction to Vassiliev's theory,
which contains the proof of the 4-term relation for chord diagrams from
the 4-term relation for knots, invented by the authors.