Figure 3From: Polynomial algorithms for the Maximal Pairing Problem: efficient phylogenetic targeting on arbitrary treesA binary tree for which only one possible path-system exists that fulfills all constraints. Leaves that must appear in the output are highlighted with an arrow, and the (only) valid path-system is displayed in color. Note that the score of the subtree T[k] = ∞, because no path-system in T[k] exists that includes all three leaves x ∈ T[k]. The score of T[h], however, is greater than 0.Back to article page