  We first present a filtration on the ring L of Laurent polynomials such that
the direct sum decomposition of its associated graded ring gr L agrees with the
direct sum decomposition of gr L, as a module over the complex general linear
Lie algebra gl(n), into its simple submodules. Next, generalizing the simple
modules occurring in gr L, we give some explicit constructions of weight
multiplicity-free irreducible representations of gl(n).
