The paper considers representations of unions and products of trees as rectangle-visibility graphs (abbreviated RVGs), i.e., graphs whose vertices are rectangles in the plane, with adjacency determined by horizontal and vertical visibility. Our main results are that the union of any tree (or forest) with a depth-1 tree is an RVG, and that the union of two depth-2 trees and the union of a depth-3 tree with a matching are subgraphs of RVGs. We also show that the cartesian product of two forests is an RVG.
['Alice M. Dean', 'Joan P. Hutchinson']
Rectangle-visibility Layouts of Unions and Products of Trees