In these data structures each tree node compares a bit slice of key values.

To define this formally, we represent each tree node as the set of vertices associated with it.

Below is a simple definition for a binary tree node.

Each subtree associates a graph vertex with a set of tree nodes.

The tree nodes are then replaced by two and the distance matrix reduced.

The groups could be presented as tree nodes.

As a base case, if G only has one vertex, its modular decomposition is a single tree node.

T-trees do not keep copies of the indexed data fields within the index tree nodes themselves.

In that case some additional information needs to be stored in the internal tree nodes to make efficient operations possible.

Additionally, the name of the tree node is printed as a heading.