Mean Semi-Open Sets

الملخص

This article introduces a new kind of mean sets that are also semi-open. Each such set contains a non-void proper semi-open set and also it is  contained in another proper semi-open set. Within this work, we compare our new concepts against the corresponding concepts that were defined via open sets. We study some fundamental properties of mean semi-open sets and their complements and provide some new results. Moreover, we investigate the behavior of such sets when they are also minimal and maximal.