Closures Of Proper Classes -2

For an integral domain R we consider the closures (formula persent) of a submodule M of an R-module N consisting of elements n of N with tn (formula persent) for some nonzero (formula persent) and its connections with usual closure M of M in N. Using these closures we study the closures (formula persent) of a proper class ℙ of short exact sequences and give a decomposition for the class of quasi-splitting short exact sequences of abelian groups into the direct sum of “p-closures” of the class Spl i t of splitting short exact sequences and description of closures of some classes. In the general case of an arbitrary ring we generalize these closures of a proper class ℙ by means of homomorphism classes ℱ and G and prove that under some conditions this closure (formula persent) is a proper classes. © 2017 Miskolc University Press