Existence of covers and envelopes of a left orthogonal class and its right orthogonal class of modules

Umamaheswaran Arunachalam, Udhayakumar Ramalingam, Selvaraj Chelliah

In this paper, we investigate the notions of ${\mathcal{X}}^{\perp }$-projective, $\mathcal{X}$-injective and $\mathcal{X}$-flat modules and give some characterizations of these modules,…