Title of article :
THE UNIT SUM NUMBER OF DISCRETE MODULES
Author/Authors :
ASHRAFI, N. semnan university - Department of Mathematics, سمنان, ايران , POUYAN, N. semnan university - Department of Mathematics, سمنان, ايران
Abstract :
In this paper, we show that every element of a discrete module is a sum of two units if and only if its endomorphism ring has no factor ring isomorphic to Z2. We also characterize unit sum number equal to two for the endomorphism ring of quasi-discrete modules with nite exchange property.
Keywords :
Unit sum number , discrete module , hollow module , lifting property
Journal title :
Bulletin of the Iranian Mathematical Society
Journal title :
Bulletin of the Iranian Mathematical Society
