Discriminating properties of compactification in discrete uniform   isotropic space-time
  Compactification of the 5-dimensional Kaluza-Klein space-time geometry is considered. The space-time geometry is supposed to be discrete, uniform and isotropic. It is shown, that consideration of the space-time geometry as a physical geometry, i.e. as a geometry described completely by the single-valued world function, leads to a discrimination of some values of the particle charge. At the conventional approach, when the world function becomes to be many-valued after compactification, the value of the elementary particle electric charge remains to be unrestricted, and this fact does not agree with experimental data. It is important, that the discrete geometry is given on the continual set of points. This circumstance makes admissible a compatibility of discreteness with the uniformity and isotropy of the geometry. 
Yuri A. Rylov