ABSOLUTE CO-SUPPLEMENT AND ABSOLUTE CO-COCLOSED MODULES

Abstract

A module M is called an absolute co-coclosed (absolute co-supplement)module if whenever M ∼= T /X the submodule X of T is a coclosed (supplement) submodule of T .are absolute co-coclosed (absolute co-supplement) are precisely determined. We also investigate the rings whose (finitely generated) absolute co-supplement modules are projective. We show that a commutative domain R is a Dedekind domain if and only if every submodule of an absolute co-supplement R-module is absolute co-supplement.We also prove that the class Coclosed of all short exact sequences