On series expansions in a nonlinear electronic system

We have studied, in the case of an electron gas moving in a magnetic field,the influence of interactions with both an electric field and the defects of the medium turned on adiabatically. We show that, depending on the order of application of these interactions, the stationary electron distribution function has two different expressions, that can be interpreted by using the Pauli master equation, but that the current-density vector is independent of the order of application of these interactions.