  The concept of dynamical symmetries is used for formulation of the
renormalization group approach to the Kondo effect in the Anderson model with
repulsive and attractive interaction $U$. It is shown that the generic local
symmetry of the Anderson Hamiltonian is determined by the SU(4) Lie group. The
Anderson Hamiltonian is rewritten in terms of the Gell-Mann matrices of the
4-th rank, which form the set of group generators and the basis for
construction of irreducible vector operators describing the excitation spectra
in the charge and spin sectors. The multistage Kondo sceening is described in
terms of the local SU(4) dynamical symmetry. It is shown that the similarity
between the conventional Kondo cotunneling effect for spin 1/2 in the positive
$U$ model and the Kondo resonance for pair tunneling in the negative $U$ model
is a direct manifestation of implicit SU(4) symmetry of the Anderson/Kondo
model.
