Fix a strictly increasing right continuous with left limits function W: \bb
R \to \bb R and a smooth function \Phi : [l,r] \to \bb R, defined on some
interval [l,r] of \bb R, such that 0<b≤Φ′≤b−1. We prove that
the evolution, on the diffusive scale, of the empirical density of exclusion
processes, with conductances given by W, is described by the weak solutions
of the non-linear differential equation ∂tρ=(d/dx)(d/dW)Φ(ρ). We derive some properties of the operator (d/dx)(d/dW) and prove
uniqueness of weak solutions of the previous non-linear differential equation