% if N == 2, we maximise P_cond_y(Y(2),X(2)) * P_x_Markov_simple(X(2),X(1)) * P_cond_y(Y(1),X(1)) with P_x_Markov_simple(X(2),X(1)) = 0 if delta_X is negative, and uniform proba otherwise
% if N == 2, we maximise P_cond_y(Y(2),X(2)) * P_x_Markov_simple(X(2),X(1)) * P_cond_y(Y(1),X(1)) with P_x_Markov_simple(X(2),X(1)) = 0 if delta_X is negative, and uniform proba otherwise