An ADS module is a direct sum of mutually injective modules, and an e-ADS module is a
direct sum of mutually automorphism-invariant modules. In this paper, we introduce and …

We show that if perspectivity is transitive in a Utumi-module M, then E (M) satisfies the
substitution property. Moreover, we also prove that if M is either a quasi-continuous or an …

A right module over a ring is called small dual-ADS, if for each decomposition then and are
mutually small projective. Small dual-ADS modules are the dual analogue of LADS …

Direct complements in a right R-module M are said to be almost unique if, whenever M= A⊕
B= A⊕ C, then (B+ C)/B≪ M/B (also (B+ C)/C≪ M/C, by symmetry). We will show that this …

An R-module M is called a D4-module if 'whenever M1 and M2 are direct summands of M
with M1+ M2= M and M1~= M2, then M1∩ M2 is a direct summand of M'. Let M=⊕ i∈ IMi be …

Аннотация R-модуль M называется D4-модулем, если всякий раз, когда M1 и M2
являются прямыми слагаемыми M с M1+ M2= M и M1∼= M2, то M1\M2 является прямым …