Existence of Covers and Envelopes of a Left Orthogonal Class and Its Right Orthogonal Class of Modules

A Umamaheswaran, R Udhayakumar… - Journal of …, 2022 - Wiley Online Library
In this paper, we investigate the notions of X⊥‐projective, X‐injective, and X‐flat modules
and give some characterizations of these modules, where X is a class of left modules. We …