vertexCut(T,e,l,newl)
vertexCut(T,E,l,newl)
Vertices of a tree of class LeafTree do not have explicit names. Therefore a vertex v is specified by naming an edge e incident to v, and leaf l on the opposite side of the edge as v.
The function outputs the subtrees of T obtained by deleting the vertex v from T and then readding v to each of the resulting subtrees as a new leaf. The new leaf on each subtree is adjacent to the edge previously adjacent to v on T. Each subtree has a copy of the vertex labeled newl, but their edge sets form a partition of the edge set of T.
Each subtree in P has one leaf that was not a leaf of T, and therefore previously unlabeled. The label for this new leaf is input as newl.





The object vertexCut is a method function.