# Contents

## Bisimplicial abelian groups

###### Proposition

Let $A,B : \Delta^{op} \times \Delta^{op} \to Ab$ be bisimplicial abelian groups. A morphism $f : A \to B$ which is degreewise in one argument a weak equivalence $f_{n,\bullet} : A(n,\bullet) \to B(n,\bullet)$ induces a weak equivalence $d(f) : d(A) \to d(B)$ of the associated diagonal complexes.

###### Proof

This is Lemma 2.7 in chapter 4 of (GoerssJardine)

## References

• Rick Jardine, Lecture 008 (2010) (pdf)

• Samuel Issacson?, Excercises in homotopy colimits (pdf)

Created on August 9, 2011 01:02:51 by Urs Schreiber (194.81.173.175)