  The possibility of unified description of hadron multiple production in heavy
ion collisions over the wide energy interval, from few hundreds MeV/n at
GSI/SIS through 11 GeV/n at BNL/AGS up to 160 GeV/n at CERN/SPS, has been
emphasized recently by J. Cleymans and K. Redlich. They, and somewhat later B.
Muller and J. Rafelski, treated this fact as an indication that quark-gluon
plasma (QGP) can be produced even at very low energies of impinging nuclei. In
our opinion, it rather witnesses that a massive constituent quark (valon) - not
massless current quark and gluon! - is just what becomes "quite easily" to be
unbound, and thus supports the expectation that in course of compression and
heating from hadronic state to QGP (or, vice versa, of expansion and cooling
down from QGP to hadronic state) nuclear matter should pass through an
intermediate phase in between.
