In algebra, an integrable module (or integrable representation) of a Kac–Moody algebra g {\displaystyle {\mathfrak {g}}} (a certain infinite-dimensional Lie algebra) is a representation of g {\displaystyle {\mathfrak {g}}} such that (1) it is a sum of weight spaces and (2) the Chevalley generators e i , f i {\displaystyle e_{i},f_{i}} of g {\displaystyle {\mathfrak {g}}} are locally nilpotent. For example, the adjoint representation of a Kac–Moody algebra is integrable.