What is the corresponding pattern topology tree in GDtype_stat.txt

[liudaliang]

I have a batch of gene trees involving two species, S1, and S2, and have obtained GD node information. But in the GDtype_stat.txt file, there are only three types of statistics, AABB, AXBB, and AAXB. AABB I understand is ((S1, S2), (S1, S2)), if I need to know the AXBB topology, how do I determine whether its topology is ((S1, X), (S1, S2)) or ((X, S2), (S1, S2))?

I hope to get your answer to help, thank you