  We consider a classical analogue of the well known quantum two-slit
experiment. Charged particles are scattered on flat screen with two slits and
hit the second screen. We show that the probability distribution on the second
screen when both slits are open is not given by the sum of distributions for
each slit separately, but has an extra interference term that is given with the
quantum rule of the addition of probabilistic alternatives. We show that the
proposed classical model has a context dependence and could be adequately
described with contextual formalism.
