The left factor of this tensor product is the set of real numbers (in this case representing lengths of edges of polyhedra) and the right factor represents dihedral angles in radians, given as numbers modulo 2. (Some sources take the angles modulo instead of modulo 2, or divide the angles by and use formula_2 in place of formula_3 but this makes no difference to the resulting tensor product, as any rational multiple of in the right factor becomes zero in the product.)