Show that the sequence is convergence in probability and set the limit of it: $$\sum\limits_{k=n}^{2n-1}\left(W_{(k+1)/n}^2-W_{k/n}^2-\frac{1}{n}\right)\left(W_{(k+1)/n}-W_{k/n}\right).$$
If there wasn't square it would be very similar to definition of integral with respect to Wiener process. But it isn't. Please help me :(
Susan ;*