Fig. 2.

Example of the application of the algorithm on two genes trees, G₁ and G₂, a species tree S and an adjacency list shown on the line Input. The costs are C(Gain)= C(Break)= 1. All the costs c_b(E_i,E_j) are computed for b∈0,1, E ∈A,B,C, i,j ∈[1..8], with E_i in G₁ and E_j in G₂. As a result c₀(C₅,C₈) = 2 while c₁(C₅,C₈) = 1. Therefore, the adjacency forest on the line Output contains C₅C₈. The left tree has cost 0 while the right one costs C(Gain)= 1 for the gain of the adjacency B₁B₃