}_{0}=[0,0,0,0],$$ and the fuzzy events are $$\widetilde{u}=\left[ \begin{array}{cccc} 0 &\ 0 &\ 0 &\ 0\\ 0 &\ 0 &\ 0 &\ 0\\ 0 &\ 0 &\ 0 &\ 0\\ 0 &\ 0 &\ 0 &\ 0\\ \end{array} \right], \hskip 0mm \widetilde{b}=\left[ \begin{array}{cccc} 0 &\ 0 &\ 0 &\ 0\\ 0 &\ 0 &\ 0 &\ 0\\ 0 &\ 0 &\ 0 &\ 0\\ 0 &\ 0 &\ 0 &\ 0\\ \end{array} \right].$$