S-object

comes with an action[note 1] of the symmetric group

The category of combinatorial species is equivalent to the category of finite

-sets (roughly because the permutation category is equivalent to the category of finite sets and bijections.

of finite-dimensional vector spaces over a field k of characteristic zero (the symmetric groups act from the right by convention).

-module determines a Schur functor on

-module shares its name with the considerably better-known model for highly structured ring spectra due to Elmendorf, Kriz, Mandell and May.

This topology-related article is a stub.