  From the previously obtained solutions of the Fokker - Planck equation for
Rayleigh gas (small impurity of heavy particles in a thermostat of light
particles) with sources and without them, the entropy production was
calculated. In a system without source (isolated system) shown that it holds
theorem of Prigogine, and in a system with sources (open system) implementation
of the principle of Ziegler (MEPP) depends on the relaxation direction. In an
open system entropy production is compensate by a negative production of
entropy, i.e. by a negentropy production. The algebraic sum of entropy and
negentropy productions is called the generalized entropy production. From the
balance of entropy and negentropy productions in an open system formulated a
possible variation of the second law for open systems in a form: "At the
relaxation of an open system to a nonequilibrium steady state, a generalized
entropy production decreases in absolute value and equal to zero in a
nonequilibrium steady state." Keywords: Fokker-Planck equation, Prigogine
theorem, principle of maximum entropy production, the second law, negentropy.
