Abstract:Let $R$ be a commutative ring with unit. We give some criterions for determining when a direct sum of two CF-modules over $R$ is a CF-module. When $R$ is local, we characterize the CF-modules over $R$ whose tensor product is a CF-module.
Keywords: CF-couple; CF-module; commutative ring; local ring
DOI: DOI 10.14712/1213-7243.2015.236
AMS Subject Classification: 13C05