Fig. 5

An example which can be reconciled, but which the original algorithm may recognize as irreconcilable. When mapping node x, all three neighbors are already mapped, and thus the algorithm by Ma et al. can choose any two of them as nodes u and v. If it chooses \(b_1\) and \(b_2\), it works correctly, but if it chooses \(a_1\) and \(b_1\), it will reject the tree in step 7(b)iii of the original algorithm [1, page 17 of the Supplement]