According to Dempster-Shafer theory for uncertainity management,
- $\textit{Bel}(A)+\textit{Bel}(\neg A) \leq 1$
- $\textit{Bel}(A)+\textit{Bel}(\neg A) \geq 1$
- $\textit{Bel}(A)+\textit{Bel}(\neg A) = 1$
- $\textit{Bel}(A)+\textit{Bel}(\neg A) =0$
Where $\textit{Bel}(A)$ denotes Belief of event $A$.