The empirical process $B_n(x) = \sqrt{n}(F_n(x) − F(x))$ converges weakly to a zero-mean Gaussian process, $B$, with covariance function:
$\mbox{cov}(B(x), B(y)) = F(\min\{x, y\}) − F(x)F(y)$.
How I can prove this assumption (about covariance function)?