  In a recent paper [Phys. Lett. A {\bf335}, 351 (2005)] the authors discussed
the equivalence among the various probability distribution functions of a
system in equilibrium in the Tsallis entropy framework. In the present letter
we extend these results to a system which is out of equilibrium and evolves to
a stationary state according to a nonlinear Fokker-Planck equation. By means of
time-scale conversion, it is shown that there exists a ``correspondence'' among
the self-similar solutions of the nonlinear Fokker-Planck equations associated
with the different Tsallis formalisms. The time-scale conversion is related to
the corresponding Lyapunov functions of the respective nonlinear Fokker-Planck
equations.
