“…The question then is: Are the long time dynamics of the two replicas sensible to small differences in initial conditions? This has been extensively studied in cellular automata (Martins, Verona de Resende, Tsallis andde Magalhães 1991, Hinrichsen, Weitz andDomany 1996), neural networks (Tamarit and Curado 1994), ferromagnetic Ising models (Stanley, Stauffer, Kertesz andHerrmann 1987, Derrida andWeisbuch 1987) and spin glasses (Derrida 1989). The quantities of interest are the Hamming distance at time t between the two replicas:…”