Purely W-extending modules
摘要
The main purpose of this work is to offer an extension of the purely extending module by using the notions of the pure submodule and the weak essential submodule. This extension is named a purely W-extending module. Actually, purely extending module locates between extending and purely W-extending modules, the author verified by example that the purely W-extending is a proper extension of purely extending module. Several results that satisfied in extending modules are extended to this new kind of modules, for instance this work studied when the submodule of purely W-extending is purely W-extending, and discussed the direct sum of this kind of modules. In addition, another characterization of purely W-extending module was considered. Besides that, proper subclasses of the purely W-extending were investigated as well as purely extending such as Puw-semisimple and rationally extending modules. Moreover, the relationships of purely W-extending with some related modules were provided for instance, W-extending, semi-extending, purely rationally extending, monoform, almost monoform and purely monoform modules. Simply put, the location of Puw-extending with extending, W-extending and purely extending modules can be determined in the Figure below:
Graphic Abstract