Trees of Life can be regarded as overlapping (or, rather, interpenetrating, as they are really 3-dimensional). Each Tree of Life has its own, identical inner form consisting of two sets of seven enfolded polygons joined at an edge — the path connecting Tiphareth of that tree with Yesod of the next higher tree (this is the so-called "root edge"). Apart from the hexagons, none of the corners of the polygons enfolded in adjacent trees coincide. The topmost corner of a hexagon (blue yod) coincides with the lowest corner of the hexagon enfolded in the next higher Tree.