We investigate a question initiated in the work of Sibley and Wagon, who proved that 3 colors suffice to color any collection of 2D parallelograms glued edge-to-edge. Their proof ...
We address a question posed by Sibley and Wagon. They proved that rhombic Penrose tilings in the plane can be 3colored, but a key lemma of their proof fails in the natural 3D gene...