There are several ways to do this. Suppose one starts by rotating the spins with $n=1$ to $n=2$, as shown by the thin arrow in Fig. \[figture\]. After the move the energy would change by an amount E\_p= J\[2(2/p) - (4/p)-1\]. \[activation\] This function is plotted in Fig. \[figenergy\].

Interestingly one has $\Delta E_p\le 0$ or $\Delta E_p>0$ for $p\le p_c$ or $p>p_c$, respectively. At $T_f=0$ moves with $\Delta E_p>0$ are forbidden. Therefore, for $p>p_c$ there is no possibility to destroy the textures and form domains. Other possible moves, as, for instance, a rotation from $n=1$ to $n=3$, correspond to a larger activation energy and are forbidden as well. Therefore, for $p> p_c$ textures and antitextures are stable against domain formation and the only ordering mechanism left is their growth and annihilation, much in the same way as in the XY model, leading to $z=4$. Conversely, for $p\le p_c$ textures are removed and domains are created whose competition leads to the Ising like behavior $z=2$. As already discussed, in the XY model the exponent $z=4$ is associated to the growth of the size of single textures. In order to check if the same mechanism is at work also in the 