Fig. 1
From: Forcing external constraints on tree inference using ASTRAL
Updates need for the tree completion algorithm. \(T_{b}^{1}\) and \(T_{b}^{2}\) are both completed based on Tr, generating either a binary tree or a multifurcating tree. In case 1 (\(T_{b}^{1}\)), subtree under u should be added as sister to sb to minimize RF; the highlighted green branch matches Tr, but creating a polytomy would result in a FN. In case 2 (\(T_{b}^{2}\)), the subtree under u should be added as a polytomy under sb; otherwise, the highlighted orange branch will be a FP. In the second case, restricting the output to be binary (as in the B-RF(+) algorithm) leads to suboptimal RF distances