Figure 2: ITR processes.

In the space of energy level configurations, we connect an initial configuration hⁱ∈ ^N with the final h^f∈^N by a smooth path (grey line). Given an L-step discretization of this path, we construct a sequence of LTs (arrows) sandwiched by thermalizations (circles). This process has the random work cost , where ^l is the state at the l-th step, which is Gibbs distributed G(h^l). In the limit of an infinitely fine discretization, the expected work cost is lim_L→∞〈W〉=F(h^f)−F(hⁱ). The independence of the work costs of the subsequent LTs yields lim_L→∞(〈W²〉−〈W〉²)=0, that is, the work cost is essentially deterministic.