To the real vector TeX Embedding failed! we associate the mapping TeX Embedding failed! such that TeX Embedding failed!. This is the discrete dynamical system, which is the topic of our talk. It was introduced by S. Akiyama, H. Brunotte, T. Borb\'ely, J. Thuswaldner and called shift radix system, shortly SRS. The orbits of the iterations of TeX Embedding failed! can be divergent or periodic. In the later case they can be ultimately zero or not. The distinction of these cases leads to hard algorithmic and complexity question provided TeX Embedding failed! is a rational vector. We report on topological and geometric properties of regions associated to SRS.