On the category of comodules over corings

Robert Wisbauer
2002 Mathematics and Mathematics Education  
It is well known that the category M C of right comodules over an A-coring C, A an associative ring, is a subcategory of the category of left modules * C M over the dual ring * C. The main purpose of this note is to show that M C is a full subcatgeory in * C M if and only if C is locally projective as a left A-module.
doi:10.1142/9789812778390_0026 fatcat:hsipx6p4xba2zntpnsrcjns364