2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/172670Let $\tilde{\mathfrak g}$ be an affine Lie algebra of the type $A_\ell^{(1)}$. We find a combinatorial basis of Feigin-Stoyanovsky's type subspace $W(Λ)$ given in terms of difference and initial conditions. Linear independence of the generating set is proved inductively by using coefficients of intertwining operators. A basis of $L(Λ)$ is obtained as an "inductive limit" of the basis of $W(Λ)$.27 pages, 7 figuresQuantum AlgebraRepresentation Theory17B67, 17B69, 05A19text