Original Article
Kyungpook Mathematical Journal 2010; 50(1): 101-107
Published online March 23, 2010
Copyright © Kyungpook Mathematical Journal.
When Some Complement of an EC-Submodule is a Direct Summand
Canan Celep Yücel, Denizli, Adnan Tercan, Ankara
Department of Mathematics, Faculty of Science and Art, Pamukkale University, 20070, Denizli, Turkey, Department of Mathematics, Hacettepe University, Beytepe Campus, 06532, Ankara, Turkey
Received: March 23, 2010; Revised: March 23, 2010; Accepted: March 23, 2010
A module $M$ is said to satisfy the $EC_{11}$ condition if every ec-submodule of $M$ has a complement which is a direct summand. We show that for a multiplication module over a commutative ring the $EC_{11}$ and P-extending conditions are equivalent. It is shown that the $EC_{11}$ property is not inherited by direct summands. Moreover, we prove that if $M$ is an $EC_{11}$-module where $SocM$ is an ec-submodule, then it is a direct sum of a module with essential socle and a module with zero socle. An example is given to show that the reverse of the last result does not hold.
Keywords: Extending module, ec-closed submodule, P-extending module, $C_{11}$-module, Multiplication module