Fig. 5
From: Predicting horizontal gene transfers with perfect transfer networks

The greedy Algorithm 2 can add more transfers than the minimum. 1 A network G whose leaves are on two characters a and b. 2 One possible solution output by Algorithm 2. The left clade is chosen to originate a and a transfer is greedily added above all the a’s on the right side. Then, the left clade is also chosen to originate b, but for that two more separate transfers are added. 3 A solution that is somewhat less natural, but with one less transfer