# Commit 2022-10-01 11:17 9af20344

View on Github →feat(algebraic_topology/dold_kan): decomposition of Q (#16357)
In this PR, a decomposition of the endomorphisms `Q q`

acting on `X _[n+1]`

is obtained. In the case of abelian categories, it shows that the image of `Q q`

is contained in a certain sum of images of degeneracy operators. Critical tools are also introduced in order to show (in a future PR) that the normalized Moore complex functor reflects isomorphisms.