Calculating Dempster-Shafer plausibility

A sufficient condition for the equality of the plausibility and commonality measures of the Dempster-Shafer belief calculus is developed. When the condition is met, an efficient method to calculate relative plausibility is available. In particular, the method can be used to calculate the relative plausibility of atomic hypotheses and, therefore, it can be used to find the choice that maximizes this measure. The computation is efficient enough to make Dempster-Shafer practical in some domains where computational complexity would otherwise discourage its use