Layout: [A] [B][D][E] [C]...[F] Relate: [B]->[A],[C] [D]->[B],[E],[F]
Layout: [A][B] [A]: Layout: [C][D] Relate: [C]->[D] [D]->[B.E] [B]: Layout: [E] [F] Relate: [E]->[F] [F]->[A.D]