A necessary and sufficient condition is given for a relatively-finitely presented module to
have a (monomorphic or epic) relatively flat envelope. Then those rings are characterized …

A well known problem in the theory of envelopes is to characterize those rings having the
property that every (finitely generated, finitely presented, simple) module has a projective …

The injective hull of a module M can be characterized as a homomorphism f: M~ E (with E an
injective module) such that for each homomorphism g: M--* E'with E'injective, there exists a …

868 MARTINEZ HERNANDEZ where F'is a flat and F-divisible module, can be completed
commutatively. b) The diagram can be completed only by means of autornorphisms of F. In …

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 Bican et al., it is proved that all modules over an arbitrary ring have flat covers. In this
article, we shall study rings over which flat covers of finitely generated modules are …

All the rings will be associative with identity and the modules will be unital. If M is a right
module we denote by M* the dual module Hom „(M., R) of M. If M is a right R-module, a flat …

Let R be a ring, X a class of left R‐modules, S the class of submodules of X, and Q the class
of quotient‐modules of X. It is shown that SQ is precovering (preenveloping) if and only if …

Full article: WHEN ARE PURE-INJECTIVE ENVELOPES OF FLAT MODULES FLAT? Skip
to Main Content Taylor and Francis Online homepage Taylor and Francis Online homepage …

Let ℒ be a class of right modules, whenever covers and envelopes exist, we show that if ℒ is
closed under extensions and direct summands, then P (ℒ), the class of all ℒ-projective right …