Standard modules and standard modules of level one
The author gives a general abstract proof of the statement that every higher-level integral irreducible module of an affine Lie algebra occurs in a tensor product of its level irreducible modules. The proof is based on \textit{S. Kumar}'s results [Invent. Math. 93, 117-130 (1988; Zbl 0668.17008)]. The case-by-case proof was given by \textit{C. F. Xie} [Commun. Algebra 22, 5983-6020 (1994; Zbl 0823.17035)].
higher-level integral irreducible module
scientific article; zbMATH DE number 810236