  Nonequilibrium dynamics of a Lieb-Liniger system in the presence of the
hard-wall potential is studied. We demonstrate that a time-dependent wave
function, which describes quantum dynamics of a Lieb-Liniger wave packet
comprised of N particles, can be found by solving an $N$-dimensional Fourier
transform; this follows from the symmetry properties of the many-body
eigenstates in the presence of the hard-wall potential. The presented formalism
is employed to numerically calculate reflection of a few-body wave packet from
the hard wall for various interaction strengths and incident momenta.
