Given an R-module C and a class of R-modules 𝒟 over a commutative ring R, we investigate
the relationship between the existence of 𝒟-envelopes (respectively, 𝒟-covers) and the …

Let R be a commutative ring and C a semidualizing R-module. We investigate the relations
between C-flat modules and C-FP-injective modules and use these modules and their …

Let R be a commutative ring, and let C be a semidualizing R-module. We introduce the
notion of finitely presented C-injective modules, finitely presented C-flat modules, weak C …

Let R be a commutative ring. We define and study f-projective modules with respect to a
semidualizing R-module C, which are called C–f-projective modules. As consequences, we …

In this paper, we prove that the Bass class with respect to a semidualizing bimodule C
contains all FP-injective S-modules. We introduce the definition of C-FP-injective modules …

In this paper, by taking the class of all C 3 (or D 3) right R-modules for general envelopes
and covers, we characterize a semisimple artinian ring (or a right perfect ring) via D 3-covers …

In generalizing the well-established notion of projective cover, the notions of D3-cover and
rad-projective cover were recently introduced and new characterizations of perfect and …

We prove the following results for a ring R.(a) If C is a class of right R-modules closed under
direct summands and isomorphisms, then every right R-module has an epic C-envelope if …

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 …

In this paper, we extend the notion of C-injective module to that of C-FP-injective module,
where S CR is a semidualizing bimodule over associative rings. We first obtain a result on …