After the introduction hy Enochs [9] of the concepts of (pre) erlveIope and I llrejcover of a
module 1r1 a gi\wi class F of modules, there has been great interest in tllelr stud;, specially …

We prove that (a) if R is a left coherent ring, then the weak global dimension w D (R)<= n
(n>= 2) if and only if every (n–2) th F–cosyzygy of a finitely presented right R–module has a …

Drinfeld recently suggested to replace projective modules by the flat Mittag-Leffler ones in
the definition of an infinite dimensional vector bundle on a scheme X (Drinfeld, 2006 [8]) …

Relative coherence and preenvelopes Page 1 manuscripta math. 81, 243- 262 (1993)
manuscripta mathematica 9 Springer rlag 1993 RELATIVE COHERENCE 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 …

A right R-module M is called a D 3-module, if M 1 and M 2 are direct summands of M with M=
M 1+ M 2, then M 1∩ M 2 is a direct summand of M. Following the work of Bass on projective …

Let R be a ring. Recall that a left R-module M is coherent if every finitely generated
submodule of M is finitely presented. R is a left coherent ring if the left R-module RR is …

Let R be a valuation ring and let Q be its total quotient ring. It is proved that any singly
projective (respectively flat) module is finitely projective if and only if Q is maximal …

An error in Corollary 9.32 of [C. Faith, Rings and Things and a Fine Array of Twentieth
Century Associative Algebra, Mathematical Surveys and Monographs, Vol. 65 (American …

In this paper we study a condition right FGTF on a ring R, namely when all finitely generated
torsionless right R-modules embed in a free module. We show that for a von Neuman …