“…Translations [5,19], rotations [1,2,6,13,27,28,31,37] and more generally rigid motions [22-26, 29, 32] in the Cartesian grids have been studied with various purposes: describing the combinatorial structure of these transformations with respect to R n vs. Z n [5,6,19,22,30,38], guaranteeing their bijectivity [1,2,13,27,31,32,37] or transitivity [28] in Z n , preserving geometrical properties [24,25] and, less frequently, ensuring their topological invariance [23,26] in Z n . These are non-trivial questions, and their difficulty increases with the dimension of the Cartesian grid [29].…”