  Path-Integral-Monte-Carlo simulation has been used to calculate the
properties of a two-dimensional (2D) interacting Bose system. The bosons
interact with hard-core potentials and are confined to a harmonic trap. Results
for the density profiles, the condensate fraction, and the superfluid density
are presented. By comparing with the ideal gas we easily observe the effects of
finite size and the depletion of the condensate because of interactions. The
system is known to have no phase transition to a Bose-Einstein condensation in
2D, but the finite system shows that a significant fraction of the particles
are in the lowest state at low temperatures.
