Fig. 9
From: JOA: Joint Overlap Analysis of multiple genomic interval sets
Segment tree nodes with the same index are stored in a BST and the root of BST is indexed. Blue and red colored nodes are original segment tree nodes which are linked to each other. Blue colored nodes are in fact the roots of the segment trees below them. Red colored nodes do not have any children. Parents of these blue and red colored nodes are the artificial nodes, if any