  We show that the bases of irreducible integrable highest weight module of a
non-symmetric Kac-Moody algebra, which is associated to a quiver with a
nontrivial admissible automorphism, can be naturally identified with a set of
certain invariant Langrangian irreducible subvarieties of certain varieties
associated with the quiver defined by Nakajima. In the case of non-symmetric
affine or finite Kac-Moody algebras, the bases can be naturally identified with
a set of certain invariant Langrangian irreducible subvarieties of a particular
deformation of singularities of the moduli space of instantons over A-L-E
spaces.
  The motivation of this paper comes from string/string duality and the paper
is ended with questions and speculations related to string/string duality.
