After the paper [1] was published, following information about D-extending modules pointed out by Adnan Tercan. Let $r$ be a left exact preradical in category of right $R$-modules and let $M$ $R$-module. A submodule $N$ is called provided $r(M/N)=0$. module an ES-module every direct summand $M$. ES-modules introduced A. Tercan [2]. Since socle preradical, coincide with for $r=Soc$.The author wh...

let $m$ be a right module over a ring $r$, $tau_m$ a preradical on $sigma[m]$, and$ninsigma[m]$. in this note we show that if $n_1, n_2in sigma[m]$ are two$tau_m$-lifting modules such that $n_i$ is $n_j$-projective ($i,j=1,2$), then $n=n_1oplusn_2$ is $tau_m$-lifting. we investigate when homomorphic image of a $tau_m$-lifting moduleis $tau_m$-lifting.

A module M is said to have the SIP if intersection of each pair direct summands also a summand M. In this article, we define SIPr and only exact where r left preradical for category right modules. We investigate structural properties SIPr-modules locate implications between other properties. deal with decomposition theory as well SIPr-modules. provide examples by looking at special preradicals.

Let $M$ be a right module over a ring $R$, $tau_M$ a preradical on $sigma[M]$, and$Ninsigma[M]$. In this note we show that if $N_1, N_2in sigma[M]$ are two$tau_M$-lifting modules such that $N_i$ is $N_j$-projective ($i,j=1,2$), then $N=N_1oplusN_2$ is $tau_M$-lifting. We investigate when homomorphic image of a $tau_M$-lifting moduleis $tau_M$-lifting.

For a coalgebraC , the rational functor Rat(−) : C∗ → C∗ is a left exact preradical whose associated linear topology is the family C , consisting of all closed and cofinite right ideals of C∗. It was proved by Radford (1973) that if C is right Noetherian (which means that every I ∈ C is finitely generated), then Rat(−) is a radical. We show that the converse follows if C1, the second term of th...