Before revision:  One measure in particular, related to the nearest neighbour interchange operation, allows us to define the notion of `` tree-based rank '' . This provides a subclassification within the tree-based networks themselves, identifying those networks that are ``very'' tree-based.
After revision:  One measure in particular, related to the nearest neighbour interchange operation, allows us to define the notion of " tree-based rank '' . This provides a subclassification within the tree-based networks themselves, identifying those networks that are ``very'' tree-based.