Chase's theorem on products of flat modules

For a ring $R$, t.f.a.e: 1) Every direct product of flat right $R$ modules is flat; 2) Every product of copies of $R$ is flat; 3) $R$ is left coherent.


  • F. W. Anderson and K. R. Fuller. Rings and categories of modules. (2012) @ Theorem 19.20 p 229