  We study sporadic randomness by means of a non-extensive form of Lyapunov
coefficient. We recover from a different perspective the same conclusion as
that of an earlier work, namely, that the ordinary Pesin theorem applies
(P.Gaspard and X.-J. Wang, Proc. Natl. Acad. Sci. USA {\bf85}, 4591 (1988)).
However, our theoretical analysis allows us to organize the numerical
calculations so as to reveal the slow transition from a temporary form of
non-extensive thermodynamics, corresponding to the prediction of a recent paper
(M. Buiatti, P. Grigolini, A. Montagnini, Phys. Rev. Lett {\bf 82}, 3383
(1999)), to the ordinary extensive thermodynamics. We show that the transition
takes place with a slow decay corresponding to the regression from a
non-equilibrium initial condition to equilibrium condition.
