Subject: Chain complexes over variable rings?
From: Tim Porter <t.porter@bangor.ac.uk>
Date: Tue, 09 May 2006 15:33:15 +0100

Dear All,

Does anyone know a reference (or even if it is true) as to 
whether the category of all chain complexes form a Quillen model 
category or similar?  To be more precise, we are thinking of the 
category of pair (C,R) where C is a chain complex of modules over 
the ring R, and the morphsims are similarly pairs in the obvious way.

Thanks

Ronnie Brown and Tim Porter.