  Anderson's theorem asserting, that symmetry of dynamic equations written in
the relativisitically covariant form is determined by symmetry of its absolute
objects, is applied to the free Dirac equation. Dirac matrices are the only
absolute objects of the Dirac equation. There are two ways of the Dirac
matrices transformation: (1) Dirac matrices form a 4-vector and wave function
is a scalar, (2) Dirac matrices are scalars and the wave function is a spinor.
In the first case the Dirac equation is nonrelativistic, in the second one it
is relativistic. Transforming Dirac equation to another scalar-vector
variables, one shows that the first way of transformation is valid, and the
Dirac equation is not relativistic
