2 Elementary systems on G-manifolds. 292 3 Two elementary systems: The(G G)-manifold and its subma- fold splitting underdiag(G G). 293 4 Examples of internal coordinates on(G G). 297 5 Kronecker products and two-particle state decompositions on(G G). 298 6 Fusion of two elementary systems on(G G). 300 7 Elementary systems on the Poincare-manifold. 301 7. 1 Mackey and covariant ?elds. 301 7. 2 From covariant to Mackey ?elds. 302 7. 3 Obstruction...