Quadratic-linear algebra

In mathematics, a quadratic-linear algebra is an algebra over a field with a presentation such that all relations are sums of monomials of degrees 1 or 2 in the generators. They were introduced by . An example is the universal enveloping algebra of a Lie algebra, with generators a basis of the Lie algebra and relations of the form "XY" – "YX" – ["X", "Y"] = 0.