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 …

In this paper, we define a class of relative derived functors in terms of left or right weak flat
resolutions to compute the weak flat dimension of modules. Moreover, we investigate two …

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 …

设R 和S 均是环, 本文研究了Gorenstein (n, d)-投射模及其一些基本性质, 进一步, 设f: R→ S
是一个环的满同态, 给出了Gorenstein (n, d)-投射模的一个等价刻画. Abstract: Let R and S be …

Copresented Dimension of Modules Page 1 Iranian Journal of Mathematical Sciences and
Informatics Vol. 14, No. 2 (2019), pp 153-157 DOI: 10.7508/ijmsi.2019.02.012 Copresented …

Let A be a complete and cocomplete abelian category with the additional assumption that
any direct sum and product of short exact sequences are exact. We explore the relation …

Let n≥ 2 and d≥ 0 be arbitrary fixed integers. We prove that there exists a ring R such
that:(1) R is a right (n, d)-ring;(2) R is not a right (n− 1, t)-ring for each non-negative integer …

Let R be a ring. In this paper, Gorenstein (n, d)-flat and (n, d)-Gorenstein (n, d)-injective
modules and some of their basic properties are studied. Moreover, some characterizations …

A ring R is called n-coherent if every (n− 1)-presented ideal of R is n-presented. In this
paper, the n-coherence of the perfect closure R∞ is investigated. We show that if R∞ is n …