  We present a stability result for a wide class doubly nonlinear equations,
featuring general maximal monotone operators, and (possibly) nonconvex and
nonsmooth energy functionals. The limit analysis resides on the reformulation
of the differential evolution as a scalar energy-conservation equation with the
aid of the so-called Fitzpatrick theory for the representation of monotone
operators. In particular, our result applies to the vanishing viscosity
approximation of rate-independent systems.
