Adopting the notation of the reference paper, s is the set of CVs where the system is mapped, and s is the auxiliary variable. Each point in s represents an ensemble of degenerate configurations. One can define a local probability density for s, for any values of s, namely the conditional probability density of s under a constraint on the value of s: p(s|s) = e -βF (s|s) δ(s -s')δs' e -βF (s|s) δ(s -s')dsds