# homology -- general homology functor

## Description

Most applications of this functor are dispatched through HH. If it is intended that i be of class ZZ, M be of class A, and N be of class B, then the method for computing HH_i(M,N) can be installed with code of the following form.
     homology(ZZ, A, B) := opts -> (i,M,N) -> ...