Coseparability of corings is a dual notion to separability of rings? (where one requires that the multiplication map is split).
An -coring is coseparable if the comultiplication splits as a --bicomodule morphism. In other words, there is a morphism of --bimodules such that
\Delta\circ p = (C \otimes_A p)\circ(\Delta\otimes_A C)
= (p\otimes_A C)\circ(C\otimes_A\Delta)
p\circ\Delta = C
Revised on July 2, 2009 20:42:45
by Toby Bartels