Department of Mathematics

y Introduction In paper [l] Masateru Harao and Shoichi Naguchi initiated a new concept for mathematical discussion of cellular automatic systems. This new concept is the group graph. The paper [l] shows that the group graphs proved to useful - under certain conditions - in mathematical...

I. Geometrical content of the problem for three-dimensional space can be formulated as whether the space can be filled with configurations bodies such as seen in the figure, in a lattice-like shifted arrangement, or not. Or in general, whether the n-dimensional Euclidean space can be filled by...