+
+Experiments shown that even if the dual
+function seems to be constant
+(variations between two evaluations of this one is less than $10^{-5}$)
+not all the $q_i$ have the same value, \textit{i. e.}, $\zeta$ is still large.
+For instance, even with a threshold set to $10^{-5}$ there still can be more than
+45\% of differences between two $q_i$.
+To summarize, a very small threshold is a necessary condition, but not
+a sufficient criteria to observe convergence of $q_i$.