If $x_i \in \{0,1\}$, the conditional distribution in the equation 12.27 is $σ(2J(a_i-d_i))$. I think the problem is that the definition $\eta_i=x_i(a_i-d_i)$ works only if $x_i\in \{-1,1\}$ but it is has been used also for the case $x_i \in \{0,1\}$
Hi,
there is an issue in the highlighted phrase:
If $
x_i \in \{0,1\}
$, the conditional distribution in the equation 12.27 is $σ(2J(a_i-d_i))$. I think the problem is that the definition $\eta_i=x_i(a_i-d_i)$ works only if $x_i\in \{-1,1\}
$ but it is has been used also for the case $x_i \in \{0,1\}
$