Supra-Approximation Spaces Using Mixed Degree Systems in Graph Theory

This paper is concerned with introducing and studying the o-space by using out degree system (resp. i-space by using in degree system) which are the core concept in this paper. In addition, the m-lower approximations, the m-upper approximations and o-space and i-space. Furthermore, we introduce near supraopen (near supraclosed) d. g. 's. Finally, the supra-lower approximation, supra-upper approximation, supra-accuracy are defined and some of its properties are investigated.