Figure 3

Example of a TBR operation. Depicted is an example of a TBR operation where T' = TBR _T (e, h, b). The original tree T is shown in (a). In (b), we first remove the edge above e, that is we prune the subtree T _e . Then we introduce a new node above h which will be the new root of the pruned subtree. We also introduce a new node above b – this is where we will reconnect the subtree back to T. Finally we rearrange the tree and obtain the resulting tree T' as in (c).