Variables

Without loss of generality, we assume that|Istij,1| = n2. The shaded nodes are the observed nodes and the rest are hidden nodes. The error events of learning structure in thelth layer of the latent tree (the0th layer consists of the observed nodes, and the(l + 1)st layer is the active set formed fromlth layer). Suppose nodesxi andxj are in different families. Then we consider the case (ii).