Type-1 extension

The simplest method to obtain the bounds is to identify the vertices of the local credal sets and generate a type-1 extension. The type-1 extension has four vertices, because both the credal sets K(f) and K(b) have vertices (0.4, 0.6) and (0.5, 0.5). By calculating p(d|l) for these four vertices, the bounds on p(d|l) are obtained: the lower bound on p(d|l) is 0.38615 and the upper bound is 0.44615.