# nLab graded abelian group

## Examples

A generalized homology/generalized cohomology theory is a suitable covariant functor/contravariant functor from suitable topological spaces to $\mathbb{Z}$-graded abelian groups (“cohomology groups”).

Created on February 8, 2016 at 09:34:14. See the history of this page for a list of all contributions to it.