“…The Gibbs inequality tells us then that this average work is at least as large as ∆F = F 1 −F 0 , the increase in free energy. 9 The difference W 0 −∆F is due to the irreversible nature of the abrupt energy injection, and this irreversibility means an increase of the total entropy of the system and its environment, and so, the Gibbs' inequality is, in fact, a version of the second law of thermodynamics. This excess work beyond the free-energy increase, W 0 − ∆F , which can be thought of as the "dissipated work," can easily shown to be equal to kT · D(P 0 P 1 ), where P 0 and P 1 are the canonical distributions pertaining to E 0 and E 1 , respectively.…”