As far as I remember, this was about the version of the discrete space when an NNI move along any branch is an edge in the graph (no need to have consecutive ranks for the nodes adjacent to the edge). If so, that space is very similar to NNI and in the current version of the paper could be omitted entirely.
As far as I remember, this was about the version of the discrete space when an NNI move along any branch is an edge in the graph (no need to have consecutive ranks for the nodes adjacent to the edge). If so, that space is very similar to NNI and in the current version of the paper could be omitted entirely.