  It is shown that early suggested derivation of the Boltzmann kinetic equation
for dilute hard sphere gas from the time-reversible BBGKY equations is
incorrect since in fact a priori substitutes for them definite irreversible
equations. Alternative approach to analysis of the hard sphere gas is
formulated which conserves the reversibility and makes it clear that at any gas
density one can reduce the BBGKY equations to the Boltzmann equation only in
case of spatially uniform gas.
