Extremal properties of the nonequilibrium statistical operator

From the extremum condition on the information entropy for fixed values of the thermodynamic coordinates at any past time the authors deduce the nonequilibrium statistical operator obtained earlier by one of them [3] on the basis of other considerations. The theorem of Prigogine on the minimum entropy production [4] and its generalization, namely the Glansdorf–Prigogine theorem [6], are shown to be related to the condition of maximum entropy for a quasi-equilibrium distribution.