Author/Authors :
Naghipoor، M. A نويسنده Department of Mathematics, College of Sciences, Shiraz University, P. O. Box 71454, Shiraz, Iran Naghipoor, M. A , Ershad، M نويسنده Department of Mathematics, College of Sciences, Shiraz University, P. O. Box 71454, Shiraz, Iran Ershad, M
Abstract :
Let S be a monoid and X a class of S-acts which is closed under coproducts. The object of this article is to find
conditions under which all S-acts have X-precovering. We have shown that the existence of torsion-free
precovering implies the existence of torsion-free covering. This work is an attempt to further facilitate the study of
the conjecture that all S-acts have flat cover.
