# nLab plethory

A plethory is a monoid object in the monoidal category of birings. The most famous example of such a creature is $\Lambda$, the ring of symmetric polynomials. See:

• J. Borger, B. Wieland, Plethystic algebra, Advances in Mathematics 194 (2005), 246–283. (web)
Created on June 29, 2010 00:31:03 by John Baez (99.11.157.15)