  A. Peres constructed an example of particles entangled in the state of spin
singlet. He claimed to have obtained the CHSH inequality and concluded that the
violation of this inequality shows that in a measurement in which some
variables are tested, other variables, not tested, have no defined value. In
the present paper is proved that the correct conclusion of the violation of the
CHSH inequality is different. It is proved that the classical calculus of
probabilities of test results, obeying the Kolmogorov axioms, is unfit for the
quantum formalism, dominated by probability amplitudes.
