2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101216We give a formula for the q-characters of arbitrary highest-weight integrable modules of sl_{r+1} as a linear combination of the fermionic q-characters of special fusion products of integrable modules. The coefficients in the sum are entries of the inverse matrix of generalized Kostka polynomials, which are in Z[q^{-1}]. In this paper we prove the relation between the character of the Feigin-Loktev graded tensor product and the generalized Kostka polynomial. We also prove the fermionic formula for the q-characters of the (unrestricted) fusion products of rectangular highest-weight integrable g-modules.31 pages, 2 figures; v2: final version, to appear in CMPRepresentation TheoryMathematical PhysicsCombinatoricstext