Let A be an integral domain with field of fractions K. We investigate the structure of the
overrings B⊆ K of A that are well-centered on A in the sense that each principal ideal of B is …

The class group of any integral domain has been introduced in [Bv], and its general
properties have been studied by several authors (see for example [A],[AA],[AAZ],[AR],[GI,[GR …

For a subsemigroup S of the multiplicative semigroup of a commutative domain R, an/?-
module M is said to be S-divisible if s M= M holds for all se S; it is/zs-divisible if it is an epic …

Semi-Krull domains have been introduced by E. Matlis in [M]. An integral domain A is semi-
Krull if and only if A=(7 {A p}, where P ranges over the set of height one primes of A, this …

The study-. of torsionfree covers started in the paper by Enochs 161 and continued in 111,
where the interesting result that any module over a integral domain has a torsionfree cover …

An E-ring is a ring that is naturally isomorphic to the endomorphism ring of its additive group.
E-rings with various properties have been constructed in the literature; we now consider …

Let A be an Grothendieck category and C a full subcategory of A. It is well known when the
inclusion functor ic: C-+ A ad~ nits a right adjoint functor. If this is the case and F: A--+ C is …

Covers of Modules over a Fixed Ring Page 1 Ž . JOURNAL OF ALGEBRA 197, 479491 1997
ARTICLE NO. JA977130 Covers of Modules over a Fixed Ring JR Garcıa Rozas* and B …

In this note, R will denote a domain (always commutative) with 1 and Q# R its field of
quotients. The R-module Q/R will be denoted by K. By the R-topology of an R-module M is …

L. FUCHS*(New Orleans) and LM PRETORIUS (Pretoria) w Introduction. A remarkable
result in abelian group theory is Hulanicki's theorem (see [6] or [2, p. 176]) stating that, for …