  Only the "anti-Ito" integral yields the correct shift of the mean, by the
fact that the elements of its Riemannian sum hold in the order O(dt) rather
than only in O(sqrt dt). The corresponding "full" Fokker-Planck equation is
particularly simple and the only one applying for Brownian motion with an
arbitrary friction law. The "full" backward equation coincides with it in the
noise contribution.
