الفهرس 
Near open and near closed setsOnly 14 pages are availabe for public view
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Abstract
In this thesis, we introduce the concepts of y-open and y-closed sets and by using them we define the notions of y-continuity, y-open, y-closed mappings and y-homeomorphism. Some of their characterizations and colltlections between them with other corresponding ones are studied. Also, many y-topological concepts as y-closure, ?-interior, ?-exterior, . . . etc and y-density are investigated. we introduce and study the concept of y-compact space. The connections between some types of mappings and y-compact spaces are discussed. Finally, we define y-connectedness depending on y-separation notions. Several properties and connections between these notions and other existing ones are investigated.