  It is shown that only in the case of n pion production amplitude (at n > 10),
which is symmetric enough relative to the momenta permutations, there is
appreciable probability of events with nothing but charged or nothing but
neutral pions. Significant enhancement of the probability of these events in
comparison with that follows from Poisson distribution is caused by induced
pions emission, in complete analogy with the phenomenon of the induced photon
emission in QED.
