Fig. 3
From: Inferring duplication episodes from unrooted gene trees
Equivalence relation ∼. An example of an unrooted gene tree U with one S2 star and all plateau rootings reconciled with a species tree S = (((a,b),(c,d)),e). U∗ contains five edges and induces three ∼-equivalence classes. The first consists of an empty edge 〈e,v〉, the second of 〈d,v〉 while the last class consists of the remaining three edges. These three classes induce rootings {G1}, {G5} and {G2,G3,G4}, respectively. Observe, that \(\widetilde {G}_{2} = \widetilde {G}_{3} = \widetilde {G}_{4}\) consist of a subset of U∗ leaves and a speciation (different for each class) at node v which is a center of S2 star