  We show how the discrete symmetries $Z_2$ and $Z_3$ combined with the
superposition principle result in the $SL(2, {\bf C})$-symmetry of quantum
states. The role of Pauli's exclusion principle in the derivation of the SL(2,
C) symmetry is put forward as the source of the macroscopically observed
Lorentz symmetry, then it is generalized for the case of the Z3 grading
replacing the usual Z2 grading, leading to ternary commutation relations. We
discuss the cubic and ternary generalizations of Grassmann algebra. Invariant
cubic forms are introduced, and their symmetry group is shown to be the
$SL(2,C)$ group The wave equation generalizing the Dirac operator to the
Z3-graded case is constructed. Its diagonalization leads to a sixth-order
equation. The solutions cannot propagate because their exponents always contain
non-oscillating real damping factor. We show how certain cubic products can
propagate nevertheless. The model suggests the origin of the color SU(3)
symmetry.
