Plethystic substitution

Plethystic substitution is a concept from the field of algebra, specifically in the context of symmetric functions and combinatorial algebra. It is a generalization of the classical notion of substitution in polynomials and symmetric functions. In mathematical terms, plethystic substitution allows one to substitute a polynomial or power sum of variables into a symmetric function, typically a generating function. The key idea is to transform one kind of function into another while preserving certain structural properties.