30 Aug
1993
30 Aug
'93
4:42 p.m.
In his 1967 thesis (but actually essentially completed by 1964) Beck defined an A-module, for an object A of a category _A_ to be an abelian group object in the slice _A_/A. This turned out to mean 2-sided A-modules, left A-modules, left A-modules and left A-modules in the categories of associative algebras, commutative (associative) algebras, groups and Lie algebras, resp., that is in all cases the desired coefficients for cohomology. This is all widely known among categorists. Has a full exposition of this ever been published and, if so, where? --Michael +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++