$]{} \[\]\[\]\[0\][${\sigma}_0$]{} \[\]\[\]\[0\][${\sigma}_0$]{} \[\]\[\]\[0\][${\sigma}_0$]{} \[\]\[\]\[0\][${\sigma}_0$]{} \[\]\[\]\[0\][${\sigma}_0$]{} \[\]\[\]\[0\][${\sigma}_0$]{} ![Left: Factor graph for a constraint satisfaction problem with $N=0$ variables (circles) and $M=0$ constraints (squares). In this example the connectivity of the function nodes is kept fixed, that is $K_a=K$ in the notations of the text. Right: Message passing procedure ($K=0$): The probability $q_{a\to 0}(u_{a\to 0})$ depends on all the probabilities $q_{b_i\to i}(u_{b_i\to i})$, $i=0,\ldots 0$ (see text).[]{data-label="fig:factor"}](figs/f