  A description of elementary particles should be based on irreducible
representations of the Poincar\'e group. In the theory of massive
representations of the full Poincar\'e group there are essentially four
different cases. One of them corresponds to the ordinary Dirac theory. The
extension of Dirac theory to the remaining three cases makes it possible to
describe an anomalous electric dipole moment of elementary particles without
breaking the reflections.
