  Certain combinatorial bases of Feigin-Stoyanovsky's type subspaces of level k
standard modules for affine Lie algebra sl(r,C)\sptilde are parametrized by
(k,r)-admissible configurations. In this note we use Capparelli-Lepowsky-Milas'
method to give a new proof of linear independence of these bases, the main
ingredient in the proof being the use of Dong-Lepowsky's intertwining operators
for fundamental sl(r,C)\sptilde-modules.
