n-FLAT AND n-FP-INJECTIVE MODULES 1. Introduction We use R-Mod (resp., Mod-R) to
denote the category of all left (resp., right) Page 1 Czechoslovak Mathematical Journal, 61 (136) …

ABSTRACT A module M is called strongly FP-injective if Ext i (P, M)= 0 for any finitely
presented module P and all i≥ 1.(Pre) envelopes and (pre) covers by strongly FP-injective …

Let $ n, d $ be two non-negative integers. A left $ R $-module $ M $ is called $(n, d) $-
injective, if ${\rm Ext}^{d+ 1}(N, M)= 0$ for every $ n $-presented left $ R $-module $ N $. A …

Let R be a ring, na fixed non-negative integer and ℱℐ n (ℱ n) the class of all left (right) R-
modules of FP-injective (flat) dimension at most n. A left R-module M (resp., right R-module …

Let R be a ring and n, k two non-negative integers. In this paper, we introduce the concepts
of n-weak injective and n-weak flat modules and via the notion of special super finitely …

Abstract A left R-module M is said to be fp-injective if, for every monomorphism K→ L with K
and L finitely presented left R-modules, Hom (L, M)→ Hom (K, M) is an epimorphism. A right …

Let R be a ring, na fixed non-negative integer and ℱ the class of all left R-modules of FP-
injective dimensions at most n. It is proved that all left R-modules over a left coherent ring R …

Let R be a ring, na fixed nonnegative integer and FP n (F n) the class of all left (right) R-
modules of FP-injective (flat) dimensions at most n. A left R-module M (resp., right R-module …

We prove that, for any n≥ 2, the classes of FP n-injective modules and of FP n-flat modules
are both covering and preenveloping over any ring R. This includes the case of FP∞ …

It is known that a ring R is left Noetherian if and only if every left R-module has an injective
(pre) cover. We show that (1) if R is a right n-coherent ring, then every right R-module has an …