« first day (3280 days earlier)      last day (108 days later) » 

9:41 AM
2
Q: A Galois connection arising from discussion concerning flat module and pure exact sequence

Zhenhui DingThere is some sort of symmetry in the definition of flat module and pure short exact sequence which can be made precise as follows. Let $R$ be a ring (with unit), $\mathcal{R}$ be the class of all right $R$-modules, and $\mathcal{S}$ be the class of all short exact sequences of left $R$-modules. ...

Hope someone could take a look at this question and offer some thoughts. Much appreciated!
 

« first day (3280 days earlier)      last day (108 days later) »