A new graph labelling on trees

Graphs are excellent structures for storing, searching, and retrieving large amounts of data. By reducing an instance of a problem to a standard graph problem, we may be able to use well-known graph algorithms to provide an optimal solution, such as graphs in bioinformatics. Binary search trees in phylogenetic trees are organized so that each node has a label. A new graph labelling on trees is defined, and the properties of trees having this labelling are shown.