Let R be a left coherent ring. We first prove that a right R-module M is strongly copure flat if
and only if Ext i (M, C)= 0 for all flat cotorsion right R-modules C and i≥ 1. Then we define …

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

If R is a right coherent ring, then left R-modules have covers by submodules of flat R-
modules if and only if all injective left R-modules have flat covers. This is the case if R is …

In this paper we show that if R is a ring of Krull dimension d and M is a strongly copure flat
(respectively, strongly copure injective) module, then E⊗ RM (respectively, HomR (E, M)) is …

Let R be a ring, na fixed non-negative integer and ℱ ℐ n (ℱ n) the class of all right (left) R-
modules of FP-injective (flat) dimension at most n. We prove that (is a perfect cotorsion …

Coherent rings with finite self-FP-injective dimension Page 1 COMMUNICATIONS IN ALGEBRA,
24(9), 2963-2980 (1996) COHERENT RINGS WITH FINITE SELF-FP-INJECTIVE DIMENSION …

Let R be a ring, M a right R-module, and na fixed non-negative integer. M is called n-
cotorsion if for any flat right R-module N. M is said to be n-flat if for any n-cotorsion right R …

Let R be a ring. A left R-module M (resp., right R-module N) is called weak injective (resp.,
weak flat) if (resp.,) for every super finitely presented left R-module F. By replacing finitely …

A ring R is called left “GF-closed”, if the class of all Gorenstein flat left R-modules is closed
under extensions. The class of left GF-closed rings includes strictly the one of right coherent …

We prove that (a) if R is left coherent, then a finitely presented right R–module M is copure
flat if and only if M is a cokernel of a flat preen-velope (b) if R is a ring and na nonnegative …