Upper M -approximate operators and M -closed sets
Jung Mi Ko, Yong Chan Kim · Journal of Intelligent & Fuzzy Systems · 2016
In this paper, we prove the existences of initial upper M -approximate operators and initial M -closed sets in commutative cl-monoids with order reverse involutions. From this fact, we define subspaces and product spaces for upper M -approximate operators and M -closed sets. Moreover, we investigate the relations between initial upper M -approximate operators and initial M -closed sets. We give their examples.