Recurrence relations for characters of affine Lie algebra Aℓ(1)

By using the known description of combinatorial bases for Feigin–Stoyanovsky’s type subspaces of standard modules for affine Lie algebra sl(l+1,C)˜, as well as certain intertwining operators between standard modules, we obtain exact sequences of Feigin–Stoyanovsky’s type subspaces at fixed level kk. This directly leads to systems of recurrence relations for formal characters of those subspaces.