The goal of this paper is to supply an explicit description of the universal decomposition algebra of the generic polynomial of degree n into the product of two monic polynomials, one of degree r, as a representation of Lie algebras of n × n matrices with polynomial entries. This is related with the bosonic vertex representation of the Lie algebra gl ∞ due to Date, Jimbo, Kashiwara and Miwa. 0 2020 MSC: 14M15, 14N15, 15A75.